tag:theconversation.com,2011:/au/topics/teenage-brain-31370/articlesTeenage brain – The Conversation2021-06-24T20:09:59Ztag:theconversation.com,2011:article/1633512021-06-24T20:09:59Z2021-06-24T20:09:59ZVital Signs: how to halve serious injuries and deaths from teenage driving accidents<figure><img src="https://images.theconversation.com/files/408091/original/file-20210624-27-afw1ip.jpg?ixlib=rb-1.1.0&rect=0%2C245%2C4000%2C2000&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>Teenage drivers are a risky bunch. They are inexperienced and don’t always drive carefully, sometimes with tragic consequences. Various studies indicate <a href="https://www.nber.org/system/files/working_papers/w28707/w28707.pdf">15-30% of teens</a> have an accident in their first year of driving. In many countries driving fatalities are the leading cause of death among teenagers.</p>
<p>The policy question is what to do about it.</p>
<p>One can imagine a number of options, from the light touch (such as information campaigns and advertisements) to the dramatic (such as raising the legal driving age).</p>
<p>Many jurisdictions have introduced laws to restrict the driving privileges of younger drivers. But it’s not always easy to tell if such laws are effective.</p>
<p>One could look at places that have the laws and compare them to accident statistics from places without such laws. But this might be misleading. </p>
<p>It is possible those laws were introduced in places with a bigger problem. Suppose the laws have reduced driving fatalities, but only to the same level as places with less severe problems in the first place. With no difference in the teen driving fatality rate between jurisdictions with or without driving restrictions, it could be incorrectly concluded the restrictions have no effect.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/more-mad-max-than-max-safety-teenagers-dont-dream-of-safe-cars-47425">More Mad Max than max safety: teenagers don't dream of safe cars</a>
</strong>
</em>
</p>
<hr>
<h2>The identification problem</h2>
<p>This is an example of what economists call the “identification problem” – figuring out how to identify the true causal effect of a policy intervention. </p>
<p>To identify the causal effect, one needs to know the right counterfactual – that is, what would have happened if the policy had not been introduced. To put it another way, the group affected by the policy needs to be compared with the right control group.</p>
<p>This is a big general issue on which economists have been working for decades. In that time many useful techniques have been developed to address the identification problem across the social sciences.</p>
<p>The development of this set of tools is what MIT economist Joshua Angrist (one of the leading scholars in this endeavour) has called “<a href="https://economics.mit.edu/files/5566">the credibility revolution</a>”.</p>
<p>It’s a revolution because we now have ways to credibly identify the causal effect of different policy interventions. That allows us to provide sensible policy prescriptions based on empirical evidence.</p>
<p>It even permits scholars to understand the size or “magnitude” of the effects and to undertake careful cost-benefit analysis.</p>
<h2>An Australian policy experiment</h2>
<p>Back to those troublesome teenage drivers. </p>
<p>In 2007 New South Wales introduced a law that banned drivers in their first year of a provisional licence from carrying two or more passengers under the age of 21 between 11pm and 5am. </p>
<p>As economists Tim Moore and Todd Morris write in a working paper published by the US National Bureau of Economic Research <a href="https://www.nber.org/papers/w28707">in April</a>, about 3% of all accidents by first-year drivers occurred while carrying multiple passengers between these hours. But these accidents accounted for about 18% of fatalities.</p>
<p>Moore (an Australian, now at Purdue University in Indiana) and Morris (at the Max Planck Institute for Social Law and Social Policy in Germany) saw the NSW policy as an ideal opportunity to test the effectiveness of teen-driving restrictions. </p>
<p>So how did they make sure they had the right counterfactual? </p>
<p>They used one of the classic techniques from the identification revolution, known as the “<a href="https://dimewiki.worldbank.org/Difference-in-Differences">difference-in-differences</a>” – or DID – method.</p>
<p>This technique was made famous (in academic and policy circles) by a path-breaking <a href="https://davidcard.berkeley.edu/papers/njmin-aer.pdf">1994 paper</a> by David Card and Alan Krueger (both then economists at Princeton University) on how minimum wage laws affect employment. </p>
<p>To put it at its simplest, rather than comparing one group to another or one group before and after a policy change, the DID method involves comparing the changes over time in one group to the changes over time in another.</p>
<p>Moore and Morris calculated changes in the restricted period (11pm–5am) then compared those to the changes in accidents during the daytime (8am–8pm). This allowed them to control for other factors affecting crash risks. </p>
<p>What they show is striking. The restriction reduced crashes by first-year drivers by 57%, and hospitalisations and fatalities by 58%. </p>
<p>With the restrictions, crashes in the 11pm-5am window dropped from about 18% to 4% of fatalities involving first-year drivers. That’s an effective policy.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/automated-vehicles-may-encourage-a-new-breed-of-distracted-drivers-101178">Automated vehicles may encourage a new breed of distracted drivers</a>
</strong>
</em>
</p>
<hr>
<h2>Long-run effects</h2>
<p>If you were sitting in an academic seminar hearing these results, you might ask: “OK, but what happens after the first-year restrictions roll off?” </p>
<p>Remarkably, Moore and Morris also find reductions in nighttime multi-passenger crashes in the second and third years. There are no clear differences in the years that follow, but by then crash rates are down to one-fifth of the first-year level.</p>
<hr>
<p><strong>Impacts on nighttime multi-passenger crashes</strong></p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/408086/original/file-20210624-17-1aaaupn.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Charts showing Immediate and subsequent impacts on night-time multi-passenger crashes, from the paper 'Shaping the Habits of Teen Drivers' by Timothy Moore & Todd Morris." src="https://images.theconversation.com/files/408086/original/file-20210624-17-1aaaupn.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/408086/original/file-20210624-17-1aaaupn.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=303&fit=crop&dpr=1 600w, https://images.theconversation.com/files/408086/original/file-20210624-17-1aaaupn.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=303&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/408086/original/file-20210624-17-1aaaupn.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=303&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/408086/original/file-20210624-17-1aaaupn.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=381&fit=crop&dpr=1 754w, https://images.theconversation.com/files/408086/original/file-20210624-17-1aaaupn.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=381&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/408086/original/file-20210624-17-1aaaupn.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=381&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
<span class="attribution"><span class="source">Timothy Moore & Todd Morris, 'Shaping the Habits of Teen Drivers', National Bureau of Economic Research, April 2021.</span></span>
</figcaption>
</figure>
<hr>
<p>In other words, these restrictions seem to have a persistent effect even after the policy intervention is no longer in place.</p>
<p>There is a broader lesson in this. Policies can have long-run effects, even after the folks targeted by the policy are no longer “being treated”. This is well known in some <a href="https://scholar.harvard.edu/fryer/publications/aligning-student-parent-and-teacher-incentives-evidence-houston-public-schools">educational interventions</a>. Experiments with small financial rewards for students and parents, for example, have shown improvements in things like attendance and performance continue even after the incentives are discontinued. It is worth looking out for with policies in other areas.</p>
<p>In any case, NSW – and Australia more generally – seems to have cracked the case on teen driver safety. </p>
<p>Thanks to Moore and Morris, and their NBER working paper, it’s an insight from which the rest of the world can learn.</p><img src="https://counter.theconversation.com/content/163351/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Richard Holden is president-elect of the Academy of the Social Sciences in Australia.</span></em></p>Australia appears to have cracked the case on teen driver safety by restricting late-night passengers.Richard Holden, Professor of Economics, UNSW SydneyLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1265822019-12-11T18:56:06Z2019-12-11T18:56:06ZHow junk food shapes the developing teenage brain<figure><img src="https://images.theconversation.com/files/306215/original/file-20191210-95130-6ls5fh.jpg?ixlib=rb-1.1.0&rect=109%2C8%2C5464%2C3152&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The teenage brain has a voracious drive for reward, diminished behavioural control and a susceptibility to be shaped by experience. This often manifests as a reduced ability to resist high-calorie junk foods.</span> <span class="attribution"><span class="source">(Shutterstock)</span></span></figcaption></figure><p>Obesity is increasing worldwide, especially among children and teenagers. <a href="https://childhoodobesityfoundation.ca/what-is-childhood-obesity/statistics/">More than 150 million children in the world are obese</a> in 2019. These children have <a href="https://www.canada.ca/en/public-health/services/publications/healthy-living/obesity-excess-weight-rates-canadian-children.html">increased risk of heart disease, cancers and Type 2 diabetes</a>. </p>
<p>Teenagers with obesity are <a href="https://www.who.int/dietphysicalactivity/childhood_consequences/en/">likely to remain obese</a> as adults. If these trends continue, <a href="https://childhoodobesityfoundation.ca/what-is-childhood-obesity/statistics/">70 per cent of adults</a> aged 40 years could be either overweight or obese by 2040.</p>
<p>I am a neuroscientist and my research investigates how diet changes the brain. I want to understand how <a href="https://doi.org/10.1002/bdr2.1173">unhealthy diets impact the developing brain</a>, and also why young people today are so prone to developing obesity. </p>
<p>Adolescents are the greatest consumers of <a href="https://theconversation.com/your-brain-on-sugar-what-the-science-actually-says-126581">calorie-rich “junk” foods</a>. During puberty, many children have an insatiable appetite as rapid growth requires lots of energy. Heightened metabolism and growth spurts can protect against obesity, to an extent. But excessively eating high-calorie junk foods and increasingly sedentary lifestyles can outweigh any metabolic protection.</p>
<h2>The teenage brain is vulnerable</h2>
<p>The teenage years are a <a href="https://science.howstuffworks.com/life/inside-the-mind/human-brain/teenage-brain1.htm">key window of brain development</a>. Adolescence coincides with a new-found social autonomy and the independence to make personal food choices. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/your-brain-on-sugar-what-the-science-actually-says-126581">Your brain on sugar: What the science actually says</a>
</strong>
</em>
</p>
<hr>
<p>During adolescence, connections between different brain regions and individual neurons are also being refined and strengthened. The adolescent brain is malleable because of <a href="https://brainworksneurotherapy.com/what-neuroplasticity">increased levels of “neuroplasticity.”</a> </p>
<p>This means the brain is highly receptive to being shaped and rewired by the environment — including diet. In turn, these changes can become hardwired when development is complete. So the adolescent brain is vulnerable to <a href="https://jamanetwork.com/journals/jamapediatrics/article-abstract/2756132">diet-induced changes</a>, but these changes may endure through life. </p>
<h2>Resisting junk food is tough</h2>
<p>Neuroscientists use <a href="https://www.sciencedaily.com/terms/functional_neuroimaging.htm">functional brain imaging</a> to examine how the brain responds to specific events. Brain scans show that the <a href="https://www.neuroscientificallychallenged.com/blog/2014/5/16/know-your-brain-prefrontal-cortex">prefrontal cortex</a> — a key brain area for behavioural control and decision-making — <a href="http://www.dx.doi.org/10.3238/arztebl.2013.0425">doesn’t fully mature until the early 20s</a>. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/306217/original/file-20191210-95125-6w25t1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/306217/original/file-20191210-95125-6w25t1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/306217/original/file-20191210-95125-6w25t1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/306217/original/file-20191210-95125-6w25t1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/306217/original/file-20191210-95125-6w25t1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/306217/original/file-20191210-95125-6w25t1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/306217/original/file-20191210-95125-6w25t1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Feelings of reward after eating food can be exaggerated due to increased numbers of dopamine receptors in the teenage brain.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<p>The prefrontal cortex controls and overrides urges triggered by events in the environment. Resisting eating a whole bag of candy or buying cheap junk foods can be particularly difficult for teenagers.</p>
<h2>Voracious drive for rewards</h2>
<p>In contrast to the immature prefrontal cortex, the <a href="https://www.neuroscientificallychallenged.com/glossary/mesolimbic-pathway">brain’s reward system</a> — the <a href="https://www.psychologytoday.com/ca/basics/dopamine">mesocorticolimbic dopamine system</a> — is fully developed at a much earlier age. </p>
<p>Teenagers are particularly drawn to rewards, including sweet and calorie-dense foods. This is due to <a href="https://doi.org/10.3389/fnbeh.2016.00189">increased numbers of dopamine receptors</a> in the adolescent brain, so the feeling of reward can be exaggerated. Frequent stimulation of the reward system results in enduring brain adaptations. </p>
<p>During adolescence, these changes may cause long-lasting shifts to the balance of brain chemicals.</p>
<p>Taken together, the teenage brain has a voracious drive for reward, <a href="https://www.seeker.com/teen-brain-wired-to-take-risks-discovery-news-1767182366.html">diminished behavioural control</a> and a susceptibility to be shaped by experience. </p>
<p>This manifests as a reduced ability to resist rewarding behaviours. So it’s not surprising that teenagers prefer to eat foods that are easy to obtain and immediately gratifying, even in the face of health advice to the contrary. But what are the enduring brain consequences?</p>
<h2>Transcranial magnetic stimulation</h2>
<p>Functional imaging studies show brain activity during tasks or viewing images of foods. Brain circuits <a href="http://www.jneurosci.org/content/36/26/6949.long">that process food rewards are more active</a> in adolescents with obesity compared to those considered normal weight. </p>
<p>Interestingly, lower activity is seen in regions of the <a href="https://doi.org/10.1111/ijpo.241">prefrontal cortex</a>. This shows that obesity can both heighten activation of the reward system and reduce brain activity in centres that can override the desire to eat.</p>
<p>Importantly, successful weight loss in adolescents <a href="https://doi.org/10.1002/oby.21004">restores levels of activity</a> in the prefrontal cortex. This provides critical knowledge that the prefrontal cortex is a key area of the brain for <a href="https://doi.org/10.1016/j.tics.2019.01.005">controlling food intake</a>, and that diet interventions increase activity in brain regions that exert self control. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/306214/original/file-20191210-95111-epoxrv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/306214/original/file-20191210-95111-epoxrv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/306214/original/file-20191210-95111-epoxrv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/306214/original/file-20191210-95111-epoxrv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/306214/original/file-20191210-95111-epoxrv.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/306214/original/file-20191210-95111-epoxrv.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/306214/original/file-20191210-95111-epoxrv.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Physical exercise boosts brain plasticity.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<p><a href="https://www.mayoclinic.org/tests-procedures/transcranial-magnetic-stimulation/about/pac-20384625">Transcranial magnetic stimulation</a> (TMS), a way scientists can modify brain activity in the prefrontal cortex, can <a href="https://doi.org/10.1016/j.neuroimage.2018.05.013">change inhibitory control</a> of eating behaviour. Repeated <a href="https://clinicaltrials.gov/ct2/show/NCT03009695">TMS treatment could be a new therapy</a> to restore cognitive control over eating, helping with long-term weight loss.</p>
<h2>Exercise boosts brain plasticity</h2>
<p>Excessively eating junk foods during adolescence could alter brain development, leading to lasting poor diet habits. But, like a muscle, the brain can be exercised to improve willpower. </p>
<p>Increased brain plasticity during adolescence means the young mind may be more receptive to lifestyle changes. <a href="https://australiascience.tv/brain-gains-how-exercise-improves-your-brain/">Physical exercise boosts brain plasticity</a>, helping to set in place new healthy habits. Identifying how the brain is changed by obesity provides opportunities to identify and intervene. </p>
<p>Functional brain imaging adds a new layer of information where clinicians can identify at-risk individuals and track brain changes during nutritional and lifestyle interventions. </p>
<p>Even more, TMS could be a new treatment approach to improve re-calibration of the young brain to prevent enduring changes into adulthood.</p>
<p>[<em>Deep knowledge, daily.</em> <a href="https://theconversation.com/ca/newsletters?utm_source=TCCA&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=deepknowledge">Sign up for The Conversation’s newsletter</a>.]</p><img src="https://counter.theconversation.com/content/126582/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Amy Reichelt receives funding from The Australian Research Council and Canada First Research Excellence Fund (BrainsCAN, Western University).</span></em></p>Excessively eating junk foods during adolescence could alter brain development, leading to lasting poor diet habits. But, like a muscle, the brain can be exercised to improve willpower.Amy Reichelt, BrainsCAN Research Fellow at Western University’s Schulich School of Medicine & Dentistry, Western UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1242392019-10-07T16:27:34Z2019-10-07T16:27:34ZStrong family ties during teen years can help ward off depression in later life<figure><img src="https://images.theconversation.com/files/295144/original/file-20191002-101470-1tpqhpk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Teens who suffer from depression tend to fare better in years to come if they have supportive families. </span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/portrait-smiling-african-american-young-mom-1289387383?src=nj7WeFusawegnQ2XmUvblg-2-65">fizkes/Shutterstock.com</a></span></figcaption></figure><p><a href="https://mphdegree.usc.edu/blog/mental-illness-and-public-health/">Depression</a> is a leading cause of disability and disease for people around the world. It often begins during adolescence, especially for females, may continue or recur in adulthood and tends to become a lifetime chronic health condition. </p>
<p><a href="https://www.who.int/news-room/fact-sheets/detail/depression">More than 300 million</a> people suffer from this mental health disorder worldwide. Depression is not only about feeling blue. It can also harm one’s social relationships, school or work and physical health. Poor mental health and depressive symptoms may also be associated with the <a href="https://www.pnas.org/content/112/49/15078;%20">recent increase in midlife premature deaths of despair</a>due to suicide, alcohol and drugs. </p>
<p>Although treatment methods and intervention efforts continue to advance, many depressive conditions remain <a href="https://doi.org/%2010.1192/bjp.184.6.526">irreversible</a>. The push for prevention and early, affordable and feasible intervention is stronger than ever, especially for young people. </p>
<p>We are <a href="http://pingchen.web.unc.edu/">both</a> <a href="https://www.cpc.unc.edu/fellow/kathleen-mullan-harris/">social demographers</a> who study family processes and health. We use a life course perspective in our research, meaning that we use longitudinal data to follow individuals as they move through various stages of life and examine how the social contexts they experience influence their health. </p>
<p>Recently we were interested in understanding how mental health changes from adolescence through mid adulthood. We wanted to see if we could identify family processes that might protect teens from depression in adolescence and later. We found that close and cohesive family relationships, understanding, and shared good times protected them then and later.</p>
<h2>Prevention a worthy goal</h2>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/295836/original/file-20191007-121060-t4b9ek.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/295836/original/file-20191007-121060-t4b9ek.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/295836/original/file-20191007-121060-t4b9ek.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/295836/original/file-20191007-121060-t4b9ek.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/295836/original/file-20191007-121060-t4b9ek.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/295836/original/file-20191007-121060-t4b9ek.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/295836/original/file-20191007-121060-t4b9ek.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Teens who feel supported by their parents during depressive episodes fare better for many years.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/mature-parents-teen-girl-smartphone-cafe-708504049?src=cGzHa5UHT8O66ZQ5J0jylQ-1-5">Lightfield Studios/Shutterstock.com</a></span>
</figcaption>
</figure>
<p>It is well known from the scientific evidence that close family relationships reduce the risks of depression during adolescence, a life stage when depression often begins, especially for girls. We were interested to know whether the mental health benefits of close and cohesive family relations in adolescence last into young adulthood, and so we used longitudinal data from a nationally-representative sample to address this question. </p>
<p>The family context is a key area that draws wide scholarly and public attention for <a href="https://www.guilford.com/books/Handbook-of-Depression-in-Children-and-Adolescents/Abela-Hankin/9781593855826/reviews">early intervention efforts</a>. Most research on the role of the family context for depression focuses on risk factors, such as neglect, abuse and financial insecurity. We wondered, however, whether preventive efforts may be more effective if focused on protective factors. We could not find major studies that could shed enough light on the topic.</p>
<p>Some small <a href="https://doi.org/%2010.1111/j.1467-8624.2007.01062.x">cross-sectional studies</a> with clinical and community samples suggest that being part of a close and cohesive family in adolescence helps alleviate depression symptoms for teenagers.</p>
<p>But does this protective effect last long into adulthood when adolescents move out of their parent’s house and embark on their independent lives? This intriguing and pressing question remains unknown due to a dearth of longitudinal studies that follow the same people over time.</p>
<p>A <a href="https://doi.org/10.1001/jamapediatrics.2019.3336">study</a>, which we published on Oct. 7 in JAMA Pediatrics is, so far as we know, the first to examine this topic in a nationally representative sample by tracking individuals over a 30-year life course from early adolescence to midlife. Our findings suggested that, yes, the protective effect not only helps in the tough teen years but also protects later.</p>
<h2>Some good news, and good insights</h2>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/295838/original/file-20191007-121051-v21t16.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/295838/original/file-20191007-121051-v21t16.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/295838/original/file-20191007-121051-v21t16.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/295838/original/file-20191007-121051-v21t16.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/295838/original/file-20191007-121051-v21t16.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/295838/original/file-20191007-121051-v21t16.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/295838/original/file-20191007-121051-v21t16.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Depression often first appears in adolescence and can come back throughout young adulthood and even middle age.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/ptsd-mental-health-concept-young-depressed-1157218930?src=y00n2Srz1y9I072Z1konMg-1-39">Chanintorn.v/Shutterstock.com</a></span>
</figcaption>
</figure>
<p>The data we used come from the <a href="https://www.cpc.unc.edu/projects/addhealth">National Longitudinal Study of Adolescent to Adult Health</a>, a nationally-representative study that has followed over 20,000 adolescents starting in 1995 into adulthood. The group of adolescents who started in the cohort have been re-interviewed five times, adding valuable knowledge about development over the course of life. The new data from the 2017 round of interviews have enabled us to examine how what happens in adolescence matters for later life mental health.</p>
<p>Our findings provide a new contribution to the research on early family experiences and lifetime depression and insights into how depression can be prevented from developing into a lifetime illness.</p>
<p>First, we found gender differences in depression over time. Females experienced significantly higher levels of depressive symptoms than males between early adolescence and their early 40s. </p>
<p>The overall trajectory of depressive symptoms was high in adolescence, fell in the early 20s, and then slowly rose again in the late 30s. The growth curve of depression is flatter for men than women. </p>
<p>Teenage girls are vulnerable to high levels of depression during middle to late adolescence. Teen boys, in comparison, experienced a shorter period of depression in late adolescence. Women then experienced the highest levels of depression in their late 30s. Men’s highest levels of depression occurred in their mid-30s to early 40s in the face of increasing challenges from work, family and social life. </p>
<p>Our primary interest, however, was to examine whether cohesive family relationships in adolescence protect young people from depression in adulthood and how long those protections last.</p>
<p>Our findings indicate the mental health benefits of cohesive family relationships during adolescence last through midlife. Individuals who experienced positive adolescent family relationships had significantly lower levels of depressive symptoms from early adolescence to midlife (late 30s to early 40s) than did those who experienced less-positive family relationships.</p>
<p>We also see this benefit working differently for men and women. Women benefit more from positive adolescent family relationships than men, especially in adolescence and the early 20s. But men with low parent-child conflict benefit for a longer time throughout young adulthood than women. </p>
<p>Living in a cohesive home, having someone around who understands and pays attention, and having fun together as a family can build up warmth, trust and attachment between the family members and adolescents and positive feelings for teens. The absence of parent-child conflict reinforces parental support and approval for them. Close relations may provide sources of social and emotional support that encourages the development of skills for coping with changing and cumulative stressors.</p>
<p>Our research findings emphasize the urgent need for early preventive interventions of depression in adolescent family life. Adolescence is a critical life stage where profound transformations in neurological, biological, cognitive and social development take place. These profound changes during adolescence make teens especially vulnerable to the development of lifetime depression. </p>
<p>Public health initiatives can teach and encourage parents and family members to nurture positive family relationships with their adolescents. Programs can be developed to promote family cohesiveness for adolescents by providing tips on how families can show affection and understanding, spend time together and work through conflict. This preventive approach will be most effective in fostering long-term healthy mental development into adulthood. </p>
<p>Our study, however, does not imply that adolescents in less cohesive families are doomed to lifetime depression. Depression is an extremely complex mental disorder. No one knows exactly what causes it. Factors such as genetics, abuse or serious illnesses can increase risks of depression too. Teens may be able to find similar sources of social support and gain coping skills through other social connections with friends, in religious and other institutions, and in the local community. </p>
<p>The skills and strategies that youth learn to cope with emotional problems may last throughout life, continue to promote mental health well into adulthood, and help to prevent negative outcomes and premature deaths due to suicide, alcohol or drugs in middle age.</p>
<p>[ <em>You’re smart and curious about the world. So are The Conversation’s authors and editors.</em> <a href="https://theconversation.com/us/newsletters?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=youresmart">You can read us daily by subscribing to our newsletter</a>. ]</p><img src="https://counter.theconversation.com/content/124239/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The teen years are filled with fun for some, but many youth begin to experience serious depression, which can set them up for recurring bouts. A new study offers hope: Support and understanding help.Ping Chen, Senior Research Scientist, University of North Carolina at Chapel HillKathleen Mullan Harris, Professor of Sociology, University of North Carolina at Chapel HillLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1117972019-03-04T22:05:20Z2019-03-04T22:05:20ZHow much sleep do teenagers really need?<figure><img src="https://images.theconversation.com/files/259160/original/file-20190214-1736-gk4n1k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Research shows that physical activity and avoiding screens before bed are both strategies to protect your teenagers' sleep.</span> <span class="attribution"><span class="source">(Unsplash/Andrea Tummons)</span>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>Parents worry about whether their teenagers are getting enough sleep. Research studies suggest that teenagers are suffering an “<a href="https://www.cbc.ca/news/health/national-sleep-deprivation-teenagers-youth-learning-1.4929842">epidemic of sleep deprivation</a>” globally — one that will have <a href="http://dx.doi.org/10.1136/bmjpo-2018-000335">long-term health impacts</a>.</p>
<p>So how much sleep do adolescents really need and how can parents help them achieve it? </p>
<p>The first thing to understand is that teenagers are still growing and their brains are still developing — so they need more sleep than adults. </p>
<p>They also have different sleep-wake rhythms and release melatonin (a natural hormone to prepare for sleep) later, which means <a href="http://dx.doi.org/10.1016/j.smrv.2014.08.002">evening sleepiness takes longer to occur</a> and they have a tendency to go to bed later and to sleep later in the morning. Of course, they still have to rise early for school. </p>
<p>Peers also influence teenagers more than they influence younger children. <a href="http://dx.doi.org/10.1016/j.jadohealth.2015.12.011">Increased social demands</a> — in the form of online chat, social networking and web browsing — combine with greater academic pressures as children enter high school. At this age parents also tend to exert less control over teenagers’ bedtimes. </p>
<h2>Eight to 10 hours, regularly</h2>
<p>So what are optimal sleep times to support adolescent health? Experts reviewed 864 papers examining relationships between children’s sleep duration and health. They suggested that those between 13 and 18 years of age should <a href="http://dx.doi.org/10.5664/jcsm.6288">sleep eight to 10 hours per 24 hours on a regular basis</a> to promote optimal health. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/259167/original/file-20190214-1742-i5ll64.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/259167/original/file-20190214-1742-i5ll64.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/259167/original/file-20190214-1742-i5ll64.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/259167/original/file-20190214-1742-i5ll64.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/259167/original/file-20190214-1742-i5ll64.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/259167/original/file-20190214-1742-i5ll64.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/259167/original/file-20190214-1742-i5ll64.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Video games at night are a recipe for disrupted, short or low-quality sleep.</span>
<span class="attribution"><span class="source">(Shutterstock)</span></span>
</figcaption>
</figure>
<p>Unfortunately, worldwide studies show that in 53 per cent of cases <a href="https://doi.org/10.1016/j.sleep.2010.11.008">teenagers are getting less than eight hours of sleep per night on school days</a>. </p>
<p>A recent report indicated that only five per cent of adolescents in the United States meet recommendations for sleep, physical activity and screen time. Older adolescents were <a href="http://www.dx.doi.org/10.1001/jamapediatrics.2018.4847">less likely than younger adolescents</a> (14 years or less) to achieve the recommendations.</p>
<h2>Sex hormones and the stress response</h2>
<p>A lot of action takes place in teenage brains due to their developmental stage. During adolescence, there are major changes to thinking, emotions, behaviour and interpersonal relationships. </p>
<p>Changes to brain connections contribute to improvements in thinking abilities and changes in brain signalling. Shifts in balance between brain systems create a period where <a href="https://doi.org/10.1016/S2215-0366(14)00081-9">teens may take increased risks or engage in more reward seeking</a>. </p>
<p>Teenagers react a lot to stress and their stress-response systems are maturing. Sex hormones affect the neurotransmitters in their brains and increase their reactivity to stress. When we add inadequate sleep time to the picture there can be many implications. </p>
<p>A recent review identified increased risk for suicide, being overweight, high rates of injury, poor sustained attention and low school grades for teens sleeping less than eight hours. </p>
<p>Sleeping nine or more hours has, on the other hand, been associated with better life satisfaction, fewer health complaints and <a href="http://dx.doi.org/10.5664/jcsm.6288">better quality family relationships for teens</a>. </p>
<p>And a recent study in two high schools in the Seattle school district found that a later school start time led to an increase in teens’ average sleep duration, which was associated with <a href="https://www.scientificamerican.com/article/the-one-change-that-boosts-a-high-schools-academic-performance/">an increase in average grades and an improvement in school attendance</a>.</p>
<h2>Drugs, alcohol and high cholesterol</h2>
<p>Teen drivers sleeping six or less hours per night on weekdays and on weekends reported riskier driving, sensation seeking and greater drug and alcohol intake than those sleeping more than six hours. </p>
<p>Less than six hours per night of sleep time <a href="https://doi.org/10.1001/jamapediatrics.2013.1429">increased the teenagers’ risk for multiple vehicle crashes</a>, after taking into account exposure to driving. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/259156/original/file-20190214-1751-zfhj2e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/259156/original/file-20190214-1751-zfhj2e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/259156/original/file-20190214-1751-zfhj2e.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/259156/original/file-20190214-1751-zfhj2e.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/259156/original/file-20190214-1751-zfhj2e.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/259156/original/file-20190214-1751-zfhj2e.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/259156/original/file-20190214-1751-zfhj2e.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Lack of sleep may be associated with greater intake of drugs and alcohol.</span>
<span class="attribution"><span class="source">(Unsplash/Ant Rozetsky)</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>There is also evidence that teens who sleep for more hours and have better quality sleep have a <a href="http://www.dx.doi.org/10.1542/peds.2017-4085">decreased risk for high blood pressure and cholesterol, insulin resistance and larger waist circumference</a> than teens with shorter sleep times and lower sleep quality. This is after taking into account other risk factors such as body fat, physical activity, television viewing and diet quality.</p>
<p>Finally, a recent report has highlighted links between teens’ <a href="https://www.psychologytoday.com/us/blog/sleep-newzzz/201901/what-modern-science-says-about-teen-sleep">sleep time, screen time and poorer mental health</a>.</p>
<h2>Park the electronic devices</h2>
<p>Parents can work with teens to set bedtimes. They should encourage the use of beds only for sleep and for relaxing before sleeping. </p>
<p>Using electronic technology before bed and during the night <a href="https://doi.org/10.1016/j.prrv.2018.10.005">increases the risk for shorter sleep time</a>. Research shows that physical activity and avoiding screens before bed are both strategies to promote earlier bedtimes and <a href="http://dx.doi.org/10.1016/j.smrv.2014.08.002">protect your teenagers’ sleep</a>. </p>
<p>Parents can support screen downtime before bedtime and through the night by parking phones at a charging pad away from bedrooms.</p>
<p>Parents can also help their teens achieve achieve the recommended eight hours or more of sleep by engaging in relaxing family activities with them in the evening.</p><img src="https://counter.theconversation.com/content/111797/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Wendy Hall does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>When teenagers sleep for less than eight hours a night, they are at increased risk of suicide, being overweight, high rates of injury, poor sustained attention and low school grades.Wendy Hall, Professor, School of Nursing, University of British ColumbiaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/925532018-04-23T13:32:57Z2018-04-23T13:32:57ZNeuroscience is unlocking mysteries of the teenage brain<figure><img src="https://images.theconversation.com/files/214078/original/file-20180410-536-1vzcx6r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/download/success?src=NyLETcK6kIFmYccPQYyA2g-4-74">Shutterstock</a></span></figcaption></figure><p>How would you describe an average teenager? For most people, the following characteristics might come to mind: moody, impulsive, risk taking, likely to succumb to peer pressure. </p>
<p>While it’s clear that adolescence is a period of life that is rife with stereotypes, there is some truth to the cliches. Many <a href="https://onlinelibrary.wiley.com/doi/abs/10.1002/hbm.23154">neuroscience studies</a> have now established that there are <a href="https://www.sciencedirect.com/science/article/pii/S1053811917300162?via%3Dihub">significant changes</a> happening in the brain in adolescence. And the things that teenagers are often derided for – like their risk taking and vulnerability to peer pressure – are actually rooted in changes occurring in the brain. There’s just one problem with this: plenty of teenagers don’t fit the stereotypes. </p>
<p>We all know from personal experience that the way teenagers think and act can vary widely depending on which teenager you’re talking about. But despite this, the <a href="http://www.cell.com/trends/cognitive-sciences/fulltext/S1364-6613(16)30007-9">vast majority of studies</a> to date have focused on averages: what happens on average to the brain during adolescence, or how do adolescents behave and feel on average?</p>
<p>Relying on averages in this way has an important statistical benefit – in that researchers are more likely to be able to detect a genuine effect if they average their findings across lots of participants. But the obvious cost is that these general findings don’t apply to everyone.</p>
<h2>Understanding individual differences</h2>
<p>In a <a href="https://www.nature.com/articles/s41593-018-0078-4">recent paper</a>, my colleagues and I argue that this needs to change. From now on, adolescent brain research needs to give more attention to these important variations between teenagers – what is known in the field as “individual differences”.</p>
<p>Besides documenting that all teenagers are different, we also need to start understanding why this is the case. Studies already investigating this have shown that genetics, <a href="https://www.nature.com/articles/pr2014171">nutrition</a>, <a href="https://www.sciencedirect.com/science/article/pii/S1878929315001280?via%3Dihub">parenting</a> and <a href="https://www.nature.com/articles/nn.4511">mental illness</a> all affect the way our brain develops and the way we behave in adolescence. And in our latest paper, we looked at three other factors that might affect brain development: socioeconomic status, relationships with peers and culture.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/214080/original/file-20180410-570-183yltq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/214080/original/file-20180410-570-183yltq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=399&fit=crop&dpr=1 600w, https://images.theconversation.com/files/214080/original/file-20180410-570-183yltq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=399&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/214080/original/file-20180410-570-183yltq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=399&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/214080/original/file-20180410-570-183yltq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=501&fit=crop&dpr=1 754w, https://images.theconversation.com/files/214080/original/file-20180410-570-183yltq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=501&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/214080/original/file-20180410-570-183yltq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=501&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Non-identikit.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/download/success?src=NyLETcK6kIFmYccPQYyA2g-2-51">Shutterstock</a></span>
</figcaption>
</figure>
<p>Socioeconomic status is a measure of a person’s social and financial standing in society, and is often gauged by their parents’ education level and the overall family income. <a href="http://www.cell.com/trends/cognitive-sciences/fulltext/S1364-6613(08)00263-5">Research</a> has already found that your brain develops differently across adolescence depending on your socioeconomic status. But what we don’t fully understand yet is why. It might be, for example, that being brought up in a lower income environment is more stressful or is linked to different types of nutrition, and that these in turn affect brain development, but more studies need to be conducted on this topic.</p>
<h2>Classmates and culture</h2>
<p>The kind of relationships that adolescents have with their classmates also affects brain activity. Adolescents with a history of being bullied, for example, show <a href="https://link.springer.com/article/10.1007%2Fs10802-015-9983-0">different patterns of brain activation</a> to certain social information – their brains appear to be more sensitive to the experience of being left out. By the same token, having lots of friends and a history of being liked by classmates also affects brain activation, and may make you more resilient to developing mental health problems. </p>
<p>Across the world, adolescents also grow up in vastly different cultures, which affects many aspects of their lives – from how many years they spend studying, to when they get married, and even how much time they spend with their families.</p>
<p>Recently, <a href="https://www.tandfonline.com/doi/abs/10.1080/17470911003687913">scientists have become interested</a> in how this might mirror differences in adolescents’ brains. We already know that adults from different cultures show interesting differences in their brain activity and brain structure, and this is now starting to be investigated in adolescents. </p>
<h2>Just your average teenager</h2>
<p>The reason why most adolescent brain research hasn’t look at individual differences yet is partly because the field is only about 20 years-old, and new research areas need to start with the basics – the averages – before they attempt to understand the nuance. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/214081/original/file-20180410-549-imonyz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/214081/original/file-20180410-549-imonyz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=377&fit=crop&dpr=1 600w, https://images.theconversation.com/files/214081/original/file-20180410-549-imonyz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=377&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/214081/original/file-20180410-549-imonyz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=377&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/214081/original/file-20180410-549-imonyz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=474&fit=crop&dpr=1 754w, https://images.theconversation.com/files/214081/original/file-20180410-549-imonyz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=474&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/214081/original/file-20180410-549-imonyz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=474&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Research into adolescent brains is a relatively new area.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/download/success?src=NyLETcK6kIFmYccPQYyA2g-1-66">Shutterstock</a></span>
</figcaption>
</figure>
<p>There are also practical reasons. Brain imaging technology to date has not been good enough to map exactly how specific factors like peer relationships might affect brain development. Then there is also the fact that to have enough power to detect reliable findings, large sample sizes are needed. </p>
<p>This means hundreds, sometimes thousands, of teenagers. At the moment a brain scan costs about £500 per hour, so sample sizes are very often limited by cost. One way to resolve this issue is for scientists to share their data with each other, and this is now starting to happen. </p>
<h2>All brains are different</h2>
<p>Recognising that all adolescents are different has really important implications for things like education or advertising. If, for example, the way in which adolescents learn is dependent on their specific pattern of brain development, then educational strategies that are based on averages will only have limited use.</p>
<p>Similarly, advertising campaigns for things like sexual health, if based on the studies that are averaged across participants, will work for some adolescents but not others.</p>
<p>The sooner we understand the difference between adolescents, the sooner we can integrate this information into schools and policy. This is important, because after all, there’s no such thing as an average teenager, and we need to remember this as we continue to refine our understanding of the adolescent brain.</p><img src="https://counter.theconversation.com/content/92553/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Lucy Foulkes has previously been funded by the Medical Research Council and employed on a grant funded by the Wellcome Trust. </span></em></p>When it comes to neuroscience, there’s no such thing as an ‘average’ teenager.Lucy Foulkes, Lecturer of Psychology in Education, University of YorkLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/824842017-09-13T02:37:05Z2017-09-13T02:37:05ZSleepy teenage brains need school to start later in the morning<figure><img src="https://images.theconversation.com/files/185684/original/file-20170912-19567-vrlesw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Their hormones mean they still need zzz's even when they're already supposed to be in homeroom.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/wake-asleep-girl-stopping-alarm-clock-315886649">Antonio Guillem/Shutterstock.com</a></span></figcaption></figure><p>Millions of high schoolers are fighting with their alarm clocks as they start another academic year. As they struggle to get up early, parents battle to get them out of bed and off to school – a stressful way for everyone involved to start the day.</p>
<p>Are teenagers just being lazy when they have to be dragged out of bed in the morning?</p>
<p>According to the National Sleep Foundation, the <a href="https://dx.doi.org/10.1016/j.sleh.2014.12.010">sleep requirement for teenagers</a> is eight to 10 hours per night. Yet, the average teen in America obtains <a href="https://doi.org/10.1111/josh.12388">less than seven hours</a> of sleep on a school night. A big part of the reason why is that nearly half of all high schools in the U.S. start before 8:00 a.m., and <a href="https://www.cdc.gov/mmWR/pdf/wk/mm6430.pdf">over 85 percent are starting before 8:30 a.m.</a></p>
<p><iframe id="r0RTS" class="tc-infographic-datawrapper" src="https://datawrapper.dwcdn.net/r0RTS/2/" height="550px" width="100%" style="border: none" frameborder="0"></iframe></p>
<p>Sleep deprivation in teenagers as a result of early school hours has been <a href="https://www.cdc.gov/media/subtopic/matte/pdf/2011/teen_sleep.pdf">a topic of concern</a> and <a href="http://www.nytimes.com/2016/03/29/upshot/schools-are-slow-to-learn-that-sleep-deprivation-hits-teenagers-hardest.html">debate</a> for over two decades. Districts <a href="https://www.bostonglobe.com/metro/2016/03/29/suburban-boston-superintendents-group-favors-later-high-school-start-time/8BdOOrfP03XP0CpuLxbchI/story.html">across the country</a> have wrestled with the question of whether their local high school <a href="http://sheu.org.uk/x/eh332ss.pdf">should start later</a>.</p>
<p>I’ve been studying the <a href="http://hdl.handle.net/11299/3902">effects of later high school start times</a> for 20 years. My research shows that teens’ inability to get out of bed before 8 a.m. has serious consequences for learning and health outcomes. Essentially, the adolescent inability to be fully awake before then is <a href="https://doi.org/10.1111/j.1467-8624.1998.tb06149.x">a matter of human biology</a> – not a matter of attitude.</p>
<h2>Gotta get to class</h2>
<p>In the earliest days of American education, students of all ages attended a single school with a single starting time. In fact, as late as 1910, half of all children <a href="https://books.google.com/books/about/Community_and_class_in_American_educatio.html?id=B3-cAAAAMAAJ">attended one-room schools</a>. As <a href="https://books.google.com/books?id=6JoOAQAAMAAJ">schools and districts grew in size</a> in the early 1930s, staggered starting times became increasingly common. The oldest students in cities and large towns were given the earliest starting time, with the thought that high school was <a href="http://dx.doi.org/10.1162/002219599551868">preparation for the adult world of work</a>. Many rural schools continue to have only a single starting time, as buses pick up students of all ages on a single run. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/185393/original/file-20170911-9457-30xndu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/185393/original/file-20170911-9457-30xndu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/185393/original/file-20170911-9457-30xndu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=254&fit=crop&dpr=1 600w, https://images.theconversation.com/files/185393/original/file-20170911-9457-30xndu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=254&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/185393/original/file-20170911-9457-30xndu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=254&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/185393/original/file-20170911-9457-30xndu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=319&fit=crop&dpr=1 754w, https://images.theconversation.com/files/185393/original/file-20170911-9457-30xndu.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=319&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/185393/original/file-20170911-9457-30xndu.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=319&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Start times can be more about district logistics than what’s best for high school students.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/dhendrix/6906652333/">dhendrix73</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>Since 2014, however, major national health organizations have taken a policy stand to support the implementation of later starting times for high school. The <a href="https://www.aap.org/en-us/about-the-aap/aap-press-room/pages/let-them-sleep-aap-recommends-delaying-start-times-of-middle-and-high-schools-to-combat-teen-sleep-deprivation.aspx">American Academy of Pediatrics</a>, the <a href="http://www.ama-assn.org/ama/pub/news/news/2016/2016-06-14-ama-supports-delayed-school-times.page">American Medical Association</a>, the <a href="http://www.cdc.gov/media/releases/2015/p0806-school-sleep.html">Centers for Disease Control and Prevention</a> and most recently the <a href="http://dx.doi.org/10.5664/jcsm.6558">American Academy of Sleep Medicine</a> have all come out with <a href="http://www.startschoollater.net/position-statements.html">statements that recommend</a> high schools start at 8:30 a.m. or later.</p>
<p>A <a href="https://www.nytimes.com/2017/05/22/well/family/the-science-of-adolescent-sleep.html">national conference</a> held in April 2017 showcased the research linking teen sleep, later high school start times and significantly positive academic, health and safety outcomes.</p>
<p>Since the experts have started to weigh in, <a href="http://www.startschoollater.net/success-stories.html">hundreds of schools</a> in 45 states across the country have been able to make the shift. In fact, the state of California is currently <a href="http://leginfo.legislature.ca.gov/faces/billNavClient.xhtml?bill_id=201720180SB328">considering a bill</a> that would require all middle and high schools in the state to start school no earlier than 8:30 a.m. by the year 2020. Legislators are starting to consider teens’ sleep deficit as an issue of public health. </p>
<h2>Why does it matter if teens are tired?</h2>
<p>Studies on <a href="https://doi.org/10.1093/sleep/11.1.100">sleep in general</a> and <a href="https://doi.org/10.1111/mbe.12059">sleep in teens in particular</a> have revealed the <a href="https://doi.org/10.1016/j.ypmed.2011.06.020">serious negative consequences</a> of lack of adequate sleep. Teens who are sleep-deprived – defined as obtaining less than eight hours per night – are significantly <a href="http://dx.doi.org/10.15585/mmwr.mm6513a1">more likely to use cigarettes, drugs and alcohol</a>. </p>
<p>The <a href="https://doi.org/10.2147/IJGM.S11557">incidence of depression among teens</a> significantly rises with less than nine hours of sleep. Around half of teens who sleep four hours or less per night <a href="https://doi.org/10.1007/s10964-014-0170-3">feel sad and hopeless</a>, compared to just 19 percent of their well-rested peers. <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2603528/">Teen car crashes</a>, the <a href="https://www.cdc.gov/nchs/data/databriefs/db37.pdf">primary cause of death for teenagers</a>, significantly decline when teens obtain more than eight hours of sleep per night.</p>
<p>A newly released report by the RAND Corporation <a href="https://www.rand.org/pubs/research_reports/RR2109.html">quantified the “costs”</a> to our society of early high school start times in terms of lost income due to impaired academic and professional performance and car crashes for teens who are sleep-deprived. The report projected annual gains to the U.S. economy of nearly US$9.4 billion over 15 years if high school starts nationwide at 8:30 a.m.</p>
<h2>Biology of the teenage brain</h2>
<p>So what exactly is going on with teenagers and their sleep patterns? Can’t they just go to bed earlier?</p>
<p>Research informing expert recommendations began in the 1980s, with <a href="http://www.sleepforscience.org/stuff/contentmgr/files/94a9f6f63ae18bc30f3d2d0b005e42fa/pdf/carskadon_pediatrician1990.pdf">studies that cast new light</a> on what goes on in the teenage brain.</p>
<p>Our brains release the sleep hormone melatonin as a signal that allows us to fall and stay asleep. In preteens and adults, the secretion of melatonin is flexible and variable, and sleep timing preferences are genetically based. But the timing is different in teens, as it is related to puberty.</p>
<p>For virtually all adolescents, the <a href="https://doi.org/10.1016/j.pcl.2011.03.003">secretion of melatonin</a> doesn’t begin until about 10:45 p.m. and continues until about 8 a.m. This means that most teenagers are <a href="https://doi.org/10.1016/j.sleep.2006.12.002">unable to fall asleep</a> until <a href="https://doi.org/10.1093/sleep/21.8.871">melatonin secretion begins</a>, and it’s hard to wake up until the melatonin secretion stops. This fixed pattern of melatonin secretion in teens changes back to an individual’s genetically preferred sleep/wake timing once puberty is over.</p>
<p>The <a href="https://doi.org/10.1093/sleep/28.11.1446">unique sleep/wake pattern of teens</a> is beyond their control. Just expecting teens to minimize distractions and <a href="http://www.sleepforscience.org/stuff/contentmgr/files/20d6c68507ee07477d59ce0d1de97b15/pdf/phi_delta_kappan.pdf">go to bed earlier</a> is not a solution. </p>
<p>I have <a href="http://hdl.handle.net/11299/139295">interviewed hundreds of teens</a> who all said that if they went to bed early, they were unable to fall asleep – they just stared at the ceiling until sleep set in around 11 p.m.</p>
<p>Researchers <a href="https://doi.org/10.1002/dev.20605">around the world</a> <a href="https://doi.org/10.1093/sleep/11.4.378">corroborated these findings</a>. At the <a href="https://doi.org/10.1093/sleep/32.12.1602">onset of puberty</a>, nearly all humans (and most mammals) <a href="https://doi.org/10.1111/j.1467-8624.2004.00655.x">experience</a> a <a href="https://www.ncbi.nlm.nih.gov/pubmed/2315238">delay of sleep timing in the brain</a>.</p>
<p>Medical researchers have also found that sleep patterns of <a href="https://doi.org/10.1016/j.sleep.2008.07.016">younger children</a> enable them to rise early and <a href="https://doi.org/10.1016/j.sleh.2015.02.004">be ready for learning</a> much earlier than adolescents. </p>
<p>In other words, the biology of the teenage brain is in <a href="https://doi.org/10.1016/j.pcl.2011.03.003">direct conflict with school schedules</a>, which typically require adolescents to begin school earlier and younger children to start later.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/185685/original/file-20170912-19534-8jtbu6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/185685/original/file-20170912-19534-8jtbu6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/185685/original/file-20170912-19534-8jtbu6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/185685/original/file-20170912-19534-8jtbu6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/185685/original/file-20170912-19534-8jtbu6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/185685/original/file-20170912-19534-8jtbu6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/185685/original/file-20170912-19534-8jtbu6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/185685/original/file-20170912-19534-8jtbu6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Well-rested students who are awake when they hit campus do better in a variety of ways.</span>
<span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/First-Day-of-School-NYC/ae5ac2c5f6c74e7199b58baf00199a2a/1/0">AP Photo/Mark Lennihan</a></span>
</figcaption>
</figure>
<h2>What happens with a later start?</h2>
<p>Results from schools that switched to a late start time are encouraging. The students <a href="https://doi.org/10.1111/josh.12388">do in fact get more sleep</a>, tending to go to bed at the same time but getting to rise a bit later in the morning. Not only does the teens’ use of drugs, cigarettes and alcohol decline; <a href="https://doi.org/10.1111/josh.12388">their academic performance</a> <a href="http://conservancy.umn.edu/handle/11299/162769">improves</a> significantly with later start time.</p>
<p>Most recently, car crash rates for <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2603528/">teen drivers have declined</a> with the implementation of a later high school start time. In fact, the crash rate for <a href="http://hdl.handle.net/11299/162769">teens in Jackson Hole, Wyoming</a> in 2013 dropped by 70 percent in the first year the district adopted a later high school start.</p>
<p>Plenty of schools and districts across the U.S. are <a href="http://www.mlive.com/news/muskegon/index.ssf/2011/12/why_do_high_school_kids_go_to.html">resisting delaying the starting time</a> of their high schools <a href="http://www.csun.edu/%7Eamg69708/prickly_politics.pdf">for many reasons</a>.</p>
<p>Issues such as changing transportation routes and altering the timing for other grade levels often head the <a href="https://doi.org/10.3102/0013189X11402323">list of factors</a> making the later start difficult. Schools also must consider the effects on <a href="http://www.aasa.org/content.aspx?id=36418">after-school sports and activities</a>.</p>
<p>Such concerns are valid. However, <a href="http://www.aasa.org/content.aspx?id=36907">schools that have delayed start times</a> found creative solutions. For example, schools adopted <a href="http://www.aasa.org/content.aspx?id=36418">mixed-age busing</a>, coordinated with public transport systems, and expanded after-school child care.</p>
<p>There’s clearly more that needs to be addressed in making the change. But, in the end, communities that value maximum development for all of its children should also be willing to grapple with solutions. </p>
<p>After all, our children’s ability to move into healthy adult lives tomorrow depends on what we as adults are deciding for them today.</p>
<p><em>This is an updated version of an <a href="https://theconversation.com/why-teen-brains-need-a-later-school-start-time-65308">article originally published</a> on Sept. 19, 2016.</em></p><img src="https://counter.theconversation.com/content/82484/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kyla Wahlstrom received a 3-year research grant from the Centers for Disease Control and Prevention to examine possible health and academic outcomes for students whose schools changed to a later starting time.</span></em></p>Teenagers aren’t just lazy. Their sleep hormones aren’t calibrated to let them get up and go until later in the morning – which has academic and health consequences when school starts too early.Kyla Wahlstrom, Senior Research Fellow in Organizational Leadership, Policy and Development, University of MinnesotaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/808922017-07-20T01:57:22Z2017-07-20T01:57:22ZThree ways to help your teenage kids develop a healthier relationship with alcohol<figure><img src="https://images.theconversation.com/files/178560/original/file-20170718-19023-1xl6c6a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Parents play an important role in when their teenage children start drinking and their drinking patterns as they grow.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/download/confirm/633035360?size=medium_jpg">from www.shutterstock.com</a></span></figcaption></figure><p>Lauren, a 15 year old school student, goes to a party at a friend’s house where the parents have supplied alcohol. She drinks too much and vomits in the car on the way home. </p>
<p>While this type of story may be common, it’s not inevitable. Our <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5461699/">new research</a> suggests parents have more of a positive influence on their teenagers’ relationship with alcohol than they realise.</p>
<p>What parents say, how they behave and the messages they send to their teenagers can <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4108600/">help delay</a> when their teenage kids start drinking, which is critical if they are to avoid the harmful and life-long effects of alcohol on the developing brain.</p>
<p>Parental influences also set the path to better <a href="https://www.ncbi.nlm.nih.gov/pubmed/15585043">drinking patterns (and reduced rates of alcohol dependence)</a> <a href="https://www.ncbi.nlm.nih.gov/pubmed/11775078">as their teenage kids</a> <a href="https://www.ncbi.nlm.nih.gov/pubmed/16818840">grow up</a>.</p>
<h2>Why are we so concerned about teenage drinking?</h2>
<p>Teenagers’ brains are <a href="http://www.sciencedirect.com/science/article/pii/S0010945212001839">still developing</a> key pathways for memory, learning, judgement and impulse control. So, damage from alcohol misuse at this critical time in development can lead to <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3960066/">cognitive issues</a> like memory problems and learning difficulties.</p>
<p>This is one reason Australian guidelines <a href="https://www.nhmrc.gov.au/_files_nhmrc/publications/attachments/ds10-alcohol.pdf">recommend</a> people under 18 avoid drinking alcohol altogether and delay starting for as long as possible.</p>
<h2>How big a problem is it?</h2>
<p>Out-of-control teenage parties often make the <a href="http://www.brisbanetimes.com.au/queensland/sunshine-coast-teen-parties-spiral-out-of-control-20161007-grx20r.html">news headlines</a>, so it’s easy to think teenage drinking is a growing problem. </p>
<p>But two <a href="http://www.aihw.gov.au/alcohol-and-other-drugs/data-sources/ndshs-2016/key-findings/">national</a> <a href="http://www.nationaldrugstrategy.gov.au/internet/drugstrategy/Publishing.nsf/content/E9E2B337CF94143CCA25804B0005BEAA/$File/National-report_ASSAD_2014.pdf">surveys</a> have confirmed drinking rates among school students (aged 12-17) and young adults (aged 18-24) are declining.</p>
<p>So, while young people may think drinking is the norm, <a href="http://www.nationaldrugstrategy.gov.au/internet/drugstrategy/Publishing.nsf/content/E9E2B337CF94143CCA25804B0005BEAA/$File/National-report_ASSAD_2014.pdf">this is not the case</a>, especially for those under the age of 15 where fewer than 15% report having drunk alcohol in the past month and 8% in the past week.</p>
<p>Nevertheless, alcohol contributes to four of the top five leading causes of death in 15-24 year olds, including <a href="http://www.aihw.gov.au/WorkArea/DownloadAsset.aspx?id=60129552757">suicide</a>, <a href="http://www.aihw.gov.au/WorkArea/DownloadAsset.aspx?id=60129552762">traffic accidents</a>, <a href="http://www.aihw.gov.au/WorkArea/DownloadAsset.aspx?id=60129552765">accidental poisoning</a> and <a href="http://www.aihw.gov.au/WorkArea/DownloadAsset.aspx?id=60129552768">assault</a>. Alcohol in this age group can also lead to <a href="http://www.jsad.com/doi/abs/10.15288/jsa.1998.59.71">sexual risk-taking</a> and is often associated with <a href="http://www.nationaldrugstrategy.gov.au/internet/drugstrategy/Publishing.nsf/content/E9E2B337CF94143CCA25804B0005BEAA/$File/National-report_ASSAD_2014.pdf">trying smoking or taking illicit drugs</a>.</p>
<p>It’s easy to think our efforts as parents to foster healthier drinking habits in our teenage children is futile. But evidence shows exactly how parents can make a difference. Here are three things you can do to help your teenage kids develop a healthier relationship with alcohol.</p>
<h2>1. Limit availability of alcohol</h2>
<p>Many parents <a href="https://www.ncbi.nlm.nih.gov/pubmed/22763230?dopt=Abstract">believe</a> supplying their children with alcohol in the safe environment of their home teaches them to drink responsibly.</p>
<p>In fact, an <a href="http://www.nationaldrugstrategy.gov.au/internet/drugstrategy/Publishing.nsf/content/E9E2B337CF94143CCA25804B0005BEAA/$File/National-report_ASSAD_2014.pdf">Australian survey found</a> parents were the most common source of alcohol with 38% of 12-17 year olds who had drunk in the past week indicating their parents gave them their last drink.</p>
<p>Unfortunately, parental supply – whether deliberate or if teenagers drink their parent’s supply behind their back – is associated with <a href="https://bmcpublichealth.biomedcentral.com/articles/10.1186/s12889-017-4472-8">heavier teen drinking</a>. And <a href="https://www.ncbi.nlm.nih.gov/pubmed/20105420">a study from the Netherlands</a> found the more adolescents drank at home, the more they were likely to drink outside of the home, which predicted future problem drinking.</p>
<p>Our study <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5461699/">also found</a> if adolescents thought they could buy alcohol easily, they were more likely to drink regularly. And the more spending money 16-17 year olds had, the more likely they were to drink.</p>
<p>The weight of the evidence is now clear. Allowing children to drink underage and supplying them with alcohol, including at parties, even under the supervision of a parent, <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4108600/">is not recommended</a>.</p>
<h2>2. Set boundaries and clear expectations</h2>
<p>Parents have a vital role to play in setting boundaries and clear expectations about drinking alcohol. Discuss alcohol with your kids and the fact <a href="http://www.aihw.gov.au/alcohol-and-other-drugs/data-sources/ndshs-2016/key-findings/">not everyone drinks</a>, even though it might seem like they do.</p>
<p>Talk about upcoming activities, including parties, and discuss expectations about acceptable and unacceptable behaviour. Talk to other parents and let them know your expectations as it’s important to set <a href="https://www.ncbi.nlm.nih.gov/pubmed/25343647">clear social norms and expectations</a>.</p>
<p>Our study <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5461699/">found</a> adolescents who thought their parents would disapprove of them drinking alcohol were much less likely to drink. This was the case across the whole age spectrum of 12-17 years. </p>
<h2>3. Be a good role model</h2>
<p>Alcohol is the <a href="http://www.aic.gov.au/crime_types/drugs_alcohol/drug_types/alcohol.html">most widely</a> used recreational drug in Australia and most adult drinking (80%) is done <a href="http://www.aihw.gov.au/WorkArea/DownloadAsset.aspx?id=60129549848">in the home</a>. So, we also need to think about our own drinking in front of our children, however uncomfortable the prospect.</p>
<p>Parents are <a href="http://journals.sagepub.com/doi/pdf/10.1080/00048674.2010.501759">important role models</a> for kids when it comes to alcohol. Setting a good example by limiting drinking in front of kids where possible, not making alcohol and drinking a key focal point, having alcohol-free events and cutting back on your own binge drinking are all significant.</p>
<p>This is important because kids who live in families where parents drink on a regular basis around their children <a href="http://journals.sagepub.com/doi/pdf/10.1080/00048674.2010.501759">are more likely</a> to drink more heavily themselves and start at an earlier age.</p>
<h2>Parents are not the only influence, but are still important</h2>
<p>While parents can play a vital role in their children’s relationship with alcohol, they are not the only factor to influence teenage drinking. </p>
<p>Alcohol is <a href="http://fare.org.au/policy/pricing-taxation/">more affordable </a> in Australia than it has been in the past 30 years, and the number of premises selling alcohol has <a href="http://nceta.flinders.edu.au/files/8713/5226/7677/EN463_LLReport_Exec_summary.pdf">increased substantially</a> in the past 15 years. Throw <a href="http://www.theage.com.au/comment/the-age-editorial/excessive-alcohol-advertising-in-sport-is-out-of-bounds-20160522-gp0x0m.html">advertising</a> and <a href="http://www.abc.net.au/news/2017-01-22/doctors-call-for-ban-on-alcohol-sponsorship-of-cricket/8198706">sports sponsorship</a> into the mix and we have some very strong messages that drinking alcohol is the norm. </p>
<p>Yet, the evidence shows parents can make significant and substantial difference in their teenage children’s relationship with alcohol, particularly in not giving them alcohol before they turn 18 and helping them set good behavioural patterns around alcohol now and for later life.</p><img src="https://counter.theconversation.com/content/80892/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jacqueline Bowden receives funding from SA Government. </span></em></p><p class="fine-print"><em><span>The research centre Robin Room heads receives funding from federal government research bodies, the Foundation for Alcohol Research and Education, VicHealth, Australian state government commissions, the U.S. National Institutes of Health and the World Health Organization. </span></em></p>Teenagers pick up cues about drinking from you and your family. Here’s how you can help them develop a healthier relationship with alcohol.Jacqueline Bowden, PhD candidate, School of Psychology, University of Adelaide and Manager, Population Health Research, South Australian Health & Medical Research InstituteRobin Room, Professor and Director, Centre for Alcohol Policy Research, La Trobe UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/672382016-10-25T19:08:01Z2016-10-25T19:08:01ZWhy sugar is so much worse for teenagers’ brains<figure><img src="https://images.theconversation.com/files/142465/original/image-20161020-8849-v0atpn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Constant sugar hits in a developing brain can change the reward centres for life, leading to behavioural and mood issues later in life. </span> <span class="attribution"><a class="source" href="http://www.shutterstock.com/downloading_tips.mhtml?code=&id=426670690&size=medium&image_format=jpg&method=download&super_url=http%3A%2F%2Fdownload.shutterstock.com%2Fgatekeeper%2FW3siZSI6MTQ3Njk3MDQ3MiwiYyI6Il9waG90b19zZXNzaW9uX2lkIiwiZGMiOiJpZGxfNDI2NjcwNjkwIiwiayI6InBob3RvLzQyNjY3MDY5MC9tZWRpdW0uanBnIiwibSI6IjEiLCJkIjoic2h1dHRlcnN0b2NrLW1lZGlhIn0sInFELy9tWWJPZTRyb1RKcWZnaVg5dEphZXV0SSJd%2Fshutterstock_426670690.jpg&racksite_id=ny&chosen_subscription=134&license=multi_share&src=zQYDiCoJVRN-yhlUOZOJUg-1-0">from www.shutterstock.com.au</a></span></figcaption></figure><p>The <a href="http://www.who.int/mediacentre/factsheets/fs311/en/">rate of obesity is increasing worldwide</a> and the increase has been particularly dramatic in young people. Young people are the greatest consumers of high-energy, sugary and fat-laden “junk” foods and sweetened drinks. </p>
<p>The heightened metabolism and rapid growth during puberty can <a href="https://www.caloriesecrets.net/its-your-duty-to-protect-your-children-from-obesity-and-here-is-how/">protect against obesity</a>. However, easy access to cheap junk foods and increasingly sedentary lifestyles outweighs the protection from growth spurts.</p>
<p>Diets high in refined sugar and saturated fat not only contribute to weight gain and <a href="http://link.springer.com/article/10.1007%2Fs00431-015-2551-3">associated health issues</a>, but also have a <a href="https://theconversation.com/study-links-obesity-with-poor-cognitive-performance-3023">profoundly detrimental impact</a> on brain function.</p>
<p>It is known excessive consumption of junk foods damage areas of the brain essential for learning and memory processes. Neurons in brain regions, including the <a href="http://www.news-medical.net/health/Hippocampus-What-is-the-Hippocampus.aspx">hippocampus</a>, that encodes memories, no longer work efficiently, leading to <a href="https://theconversation.com/junk-food-blocks-arteries-and-memory-21581">poorer learning</a>.</p>
<p>This is of great concern as adolescence is a critical formative period for learning about the world. Adolescence is also a time of newly found independence, including food choices.</p>
<p>Recent research in rodents has shown the adolescent brain is at an increased risk of developing <a href="http://journal.frontiersin.org/article/10.3389/fnbeh.2016.00189/full">diet-induced cognitive dysfunction</a>. Adolescent, but not adult, mice develop memory problems after consuming <a href="https://www.ncbi.nlm.nih.gov/pubmed?Db=pubmed&Cmd=ShowDetailView&TermToSearch=24662056">high-fat diets</a>.</p>
<p>Teenage rats that drank sugary beverages were <a href="https://www.ncbi.nlm.nih.gov/pubmed?Db=pubmed&Cmd=ShowDetailView&TermToSearch=25242636">less able to remember a specific location</a> leading to an escape hatch. This was compared to adult rats drinking sugary beverages, and teenage rats that had low-sugar diets.</p>
<p>The brains of the adolescent sugar-diet rats also showed increased levels of inflammation in the hippocampus, disrupting learning and memory function. Inflammation in the brain can contribute to cognitive decline and dementia.</p>
<p>The <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3457620/">negative effects of obesity</a> on the brain have been observed in young people too. Obese adolescents performed worse at maths, spelling and mental flexibility than healthy-weight adolescents. Structural brain scans revealed that obese teenagers had smaller hippocampi. This provides evidence that excessive body fat impacts the brain’s learning centre.</p>
<hr>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/143035/original/image-20161025-28423-18f5rht.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/143035/original/image-20161025-28423-18f5rht.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=525&fit=crop&dpr=1 600w, https://images.theconversation.com/files/143035/original/image-20161025-28423-18f5rht.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=525&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/143035/original/image-20161025-28423-18f5rht.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=525&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/143035/original/image-20161025-28423-18f5rht.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=660&fit=crop&dpr=1 754w, https://images.theconversation.com/files/143035/original/image-20161025-28423-18f5rht.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=660&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/143035/original/image-20161025-28423-18f5rht.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=660&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
<span class="attribution"><span class="source">The Conversation</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<hr>
<h2>Teenage brains are a work in progress</h2>
<p>The teenage brain undergoes major developmental changes in terms of structure and function. Adolescence is a period of increased <a href="http://yourbrainhealth.com.au/what-actually-is-neuroplasticity/">neuroplasticity</a> due to the dramatic changes in connectivity within brain regions. </p>
<p>Brain-imaging studies show that the <a href="http://www.wisegeek.org/what-is-the-prefrontal-cortex.htm">prefrontal cortex</a> doesn’t fully mature until the early 20s. A major role of the prefrontal cortex is performing executive functions. This term encapsulates behavioural control, attention and decision-making. </p>
<p>Poor regulation of the <a href="http://www.seeker.com/teen-brain-wired-to-take-risks-discovery-news-1767182366.html">prefrontal cortex during adolescence</a> can explain the increased risk taking behaviours in teenagers, including dangerous driving, drug use and binge drinking. </p>
<p><a href="https://www.cdc.gov/mmwr/pdf/ss/ss6304.pdf">Educational efforts</a> to provide teens with information about unsafe behaviours tends to fall on deaf ears. The prefrontal cortex helps us to resist performing behaviours triggered by events in the environment. Resisting these behaviours in the face of immediate reward can be difficult, particularly for teenagers. </p>
<h2>Teenage brains love rewards</h2>
<p>The risky behaviours teenagers engage in are often immediately rewarding. The <a href="http://neuroscience.mssm.edu/nestler/brainRewardpathways.html">brain’s reward system</a> releases the neurotransmitter dopamine when stimulated by pleasurable events, increasing the drive to carry out these activities. </p>
<p>Teenagers are particularly drawn to rewards, including eating tasty foods high in fat and sugar. The adolescent reward system is sensitive to stimulation and may be permanently altered by overactivation during this period. </p>
<p>Combined with the reduced ability to resist rewarding behaviours, it is not surprising that teenagers prefer to eat foods that are easy to obtain and immediately gratifying, even in the face of health advice to the contrary.</p>
<p>Changes in the brain caused by overconsumption of sugary foods during adolescence can manifest in later life as difficulties in <a href="https://www.psychologytoday.com/blog/brain-sense/200912/depression-and-anhedonia">experiencing reward</a>. Research has shown male rats that drank sugar water during adolescence showed <a href="http://journal.frontiersin.org/article/10.3389/fnbeh.2016.00189/full">reduced motivation</a> and enjoyment of rewards when they were adults. </p>
<p>These behaviours are core features of mood disorders including depression. Importantly, this shows that how we eat during adolescence can impact brain function as adults, leading to long-lasting changes in food preference and learning about rewards.</p>
<h2>Teenage brains are more plastic</h2>
<p>Excessive consumption of junk foods during adolescence could derail normal brain maturation processes. This may alter normal development trajectories, leading to enduring behavioural predispositions – in this case, the habit of consuming fatty and sugar foods, leading to obesity. </p>
<p>Fortunately, the increased plasticity of the adolescent brain means that young people may be more responsive to change. Opportunities to identify and intervene in high-risk youths may avert destructive negative behavioural spirals that may originate in adolescence. This can encourage life-long healthy habits.</p><img src="https://counter.theconversation.com/content/67238/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Amy Reichelt receives funding from the Australian Research Council.</span></em></p>Teenage rats that drank sugary beverages were less able than adult rats who drank the same to remember a specific location leading to an escape hatch.Amy Reichelt, Lecturer, ARC DECRA, RMIT UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/653082016-09-20T01:47:23Z2016-09-20T01:47:23ZWhy teen brains need a later school start time<figure><img src="https://images.theconversation.com/files/138329/original/image-20160919-11123-iy7huh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Why do teenagers need more sleep?</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/65817306@N00/2672989636/in/photolist-5ggsrD-9d4KVx-g3Zue3-aLGurP-ahBRkZ-7Qtftm-9jqybv-aXwqe-dmTFbX-e8X7rk-7BvLWV-5bhKmF-atmpzL-81Rq8b-7BuobK-9ksxY8-6AnYmL-6AiPdn-bywiVq-pHaiyM-entmaN-9dmtUD-gY67ci-8vBVPR-nVWPAe-6Q54ib-7ByFVh-dYYSa-E4L9fi-rHRZ5F-4NTFs5-8Dgdfa-bg3dAR-7Gx3uV-7Bymfh-5szpqe-aSbPCM-55cLGd-agbKxQ-6AnY5E-6Ax7wx-7jMSXn-ofcjwF-atmpCC-53RKPh-rozeKt-5Sqz9E-dgZQXD-6AiNVK-9VZHGa">Jens-Olaf Walter</a>, <a class="license" href="http://creativecommons.org/licenses/by-nc/4.0/">CC BY-NC</a></span></figcaption></figure><p>Millions of high schoolers are having to wake up early as they start another academic year. It is not uncommon to hear comments from parents such as,</p>
<blockquote>
<p>“I have a battle every morning to get my teenager out of bed and off to school. It’s a hard way to start every day.” </p>
</blockquote>
<p>Sleep deprivation in teenagers as a result of early school start has been <a href="https://www.cdc.gov/media/subtopic/matte/pdf/2011/teen_sleep.pdf">a topic of concern</a> and <a href="http://www.nytimes.com/2016/03/29/upshot/schools-are-slow-to-learn-that-sleep-deprivation-hits-teenagers-hardest.html">debate</a> for nearly two decades. School principals, <a href="https://www.bostonglobe.com/metro/2016/03/29/suburban-boston-superintendents-group-favors-later-high-school-start-time/8BdOOrfP03XP0CpuLxbchI/story.html">superintendents and school boards</a> across the country have <a href="http://sheu.org.uk/x/eh332ss.pdf">struggled with the question</a> of whether their local high school should start later.</p>
<p>So, are teenagers just lazy? </p>
<p>I have been researching the <a href="http://conservancy.umn.edu/handle/11299/3902">impact</a> of later high school start times for 20 years. <a href="http://conservancy.umn.edu/handle/11299/162769">Research findings</a> show that teens’ inability to get out of bed before 8 a.m. is a matter of human biology, not a matter of attitude. </p>
<p>At issue here are the <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2820578/">sleep patterns of the teenage brain</a>, which are different from those of younger children and adults. Due to the biology of human development, the <a href="http://www.sleepforscience.org/stuff/contentmgr/files/d2639df6ae30de274482fbac22473883/pdf/carskadon_etal._1993.pdf">sleep mechanism in teens</a> does not allow the brain to naturally awaken before about 8 a.m. This often gets into conflict with school schedules in many communities.</p>
<h2>History of school timing</h2>
<p>In the earliest days of American education, all students attended a single school with a single starting time. In fact, as late as 1910, half of all <a href="https://books.google.com/books/about/Community_and_class_in_American_educatio.html?id=B3-cAAAAMAAJ">children attended one-room schools</a>. As <a href="https://books.google.com/books?id=6JoOAQAAMAAJ&q=Education+in+the+United+States:+An+Interpretive+History.+New+York:+Free+Press&dq=Education+in+the+United+States:+An+Interpretive+History.+New+York:+Free+Press&hl=en&sa=X&ved=0ahUKEwivqvOdz5vPAhVr74MKHTnvCoQQ6AEIJTAA">schools and districts grew in size</a> in the late 1890s-1920s, staggered starting times became the norm across the country. </p>
<p>In <a href="http://www.mitpressjournals.org/doi/abs/10.1162/002219599551868#.V9_zbj4rKAw">cities and large towns</a>, high school students went first, followed by middle schoolers and then elementary students. </p>
<h2>Here’s what research shows</h2>
<p>Research findings during the 1980s started to cast a new light on teenagers’ sleep patterns.</p>
<p>Researcher <a href="https://www.brown.edu/Departments/CLPS/people/mary-carskadon">Mary Carskadon</a> and others at Brown University <a href="http://www.journalsleep.org/ViewAbstract.aspx?pid=25767">found</a> that the human brain has a <a href="http://projectneuron.illinois.edu/sites/default/files/U3_L8_Supplement_CarskadonEtal1998.pdf">marked shift</a> in its sleep/wake pattern <a href="http://www.sciencedirect.com/science/article/pii/S1389945706007076">during adolescence</a>. </p>
<p>Researchers <a href="http://www.ncbi.nlm.nih.gov/pubmed/21953482">around the world</a> <a href="http://www.ncbi.nlm.nih.gov/pubmed/3206056">corroborated those findings</a>. At the <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2786044/">onset of puberty</a>, nearly all humans (and most mammals) <a href="http://onlinelibrary.wiley.com/doi/10.1111/j.1467-8624.2004.00655.x/abstract">experience</a> a <a href="http://www.sleepforscience.org/stuff/contentmgr/files/94a9f6f63ae18bc30f3d2d0b005e42fa/pdf/carskadon_pediatrician1990.pdf">delay of sleep timing in the brain</a>. As a result, the adolescent body does not begin to feel sleepy until about 10:45 p.m. </p>
<p>At the same time, medical researchers also found that sleep patterns of <a href="http://www.sciencedirect.com/science/article/pii/S1389945708003134">younger children</a> enabled them to rise early and <a href="http://www.sciencedirect.com/science/article/pii/S2352721815000522">be ready for learning</a> much earlier than adolescents. </p>
<p>In other words, the biology of the teenage brain is <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3130594/">in conflict with early school start times</a>, whereas sleep patterns of most younger children are in sync with schools that start early.</p>
<h2>Biology of teenage brain</h2>
<p>So, what exactly happens to the teenage brain during the growth years? </p>
<p>In the teens, the secretion of the sleep hormone melatonin begins at about 10:45 p.m. and continues until about 8 a.m. What this means is that teenagers are unable to fall asleep until melatonin secretion begins and they are also not able to awaken until the melatonin secretion stops. </p>
<figure class="align-left ">
<img alt="" src="https://images.theconversation.com/files/138327/original/image-20160919-11117-g6f41d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/138327/original/image-20160919-11117-g6f41d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/138327/original/image-20160919-11117-g6f41d.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/138327/original/image-20160919-11117-g6f41d.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/138327/original/image-20160919-11117-g6f41d.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/138327/original/image-20160919-11117-g6f41d.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/138327/original/image-20160919-11117-g6f41d.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">What happens to the brain during teenage years?</span>
<span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-65181187/stock-photo-human-head-and-brain-different-kind-of-waveforms-produced-by-brain-activity-shown-on-background-digital-illustration.html?src=Dez3qdc17ZB1OLuR8e_NHQ-2-17">Brain image via www.shutterstock.com</a></span>
</figcaption>
</figure>
<p>These <a href="http://www.journalsleep.org/Articles/281116.pdf">changes in the sleep/wake pattern of teens</a> are dramatic and beyond their control. Just <a href="http://www.sleepforscience.org/stuff/contentmgr/files/20d6c68507ee07477d59ce0d1de97b15/pdf/phi_delta_kappan.pdf">expecting teens to go to bed earlier</a> is not a solution. </p>
<p>I have <a href="http://conservancy.umn.edu/handle/11299/139295">interviewed</a> hundreds of teens who all said that if they went to bed early, they were unable to sleep – they just stared at the ceiling until sleep set in around 10:45 p.m.</p>
<p>According to the National Sleep Foundation, the <a href="https://sleepfoundation.org/how-sleep-works/how-much-sleep-do-we-really-need">sleep requirement for teenagers</a> is between 8-10 hours per night. That indicates that the earliest healthy wake-up time for teens should not be before 7 a.m.</p>
<p><a href="http://conservancy.umn.edu/handle/11299/162769">A recent research study that I led</a> shows that it takes an average of 54 minutes from the time teens wake up until they leave the house for school. With nearly half of all high schools in the U.S. starting before 8:00 a.m., and <a href="http://nces.ed.gov/surveys/sass/tables/sass1112_201381_s1n.asp">over 86 percent starting before 8:30 a.m.</a>, leaving home by 7:54 a.m. would be a challenge for most teens in America.</p>
<h2>What happens with less sleep</h2>
<p><a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2517096/">Studies on sleep</a> in general, and on <a href="http://www.apa.org/topics/sleep/why.aspx">sleep in teens in particular</a>, have revealed the <a href="http://linkinghub.elsevier.com/retrieve/pii/S0091743511002878?via=sd">serious negative consequences of lack of adequate sleep</a>. Teens who are sleep-deprived – defined as obtaining less than eight hours per night – are significantly more likely to use cigarettes, drugs and alcohol. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/138325/original/image-20160919-11090-1edf9u6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/138325/original/image-20160919-11090-1edf9u6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/138325/original/image-20160919-11090-1edf9u6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/138325/original/image-20160919-11090-1edf9u6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/138325/original/image-20160919-11090-1edf9u6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/138325/original/image-20160919-11090-1edf9u6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/138325/original/image-20160919-11090-1edf9u6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">What happens with less sleep?</span>
<span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-2815896/stock-photo-portrait-of-a-student-shot-in-studio.html?src=M1jeOAq7UzBSXX55KEcmJA-1-31">Student image via www.shutterstock.com</a></span>
</figcaption>
</figure>
<p>The <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3119585/">incidence of depression among teens</a> significantly rises with less than nine hours of sleep. Feelings of sadness and <a href="http://winslerlab.gmu.edu/pubs/WinslerSleep.pdf">hopelessness increase</a> from 19 percent up to nearly 52 percent in teens who sleep four hours or less per night. </p>
<p><a href="https://ebssp.eboardsolutions.com/sites/decaturcity/Documents/Board%20Committees%202011-2012/RMS%20and%20DHS%20Start%20and%20End%20Times/Danner_2008.pdf">Teen car crashes</a>, the <a href="https://www.nhtsa.gov/road-safety">primary cause of death for teenagers</a>, are found to significantly decline when teens obtain more than eight hours of sleep per night. </p>
<h2>What changes with later start time?</h2>
<p>Results from schools that switched to a late start time are encouraging. Not only does the teens’ use of drugs, cigarettes, and alcohol decline, <a href="http://www.ncbi.nlm.nih.gov/pubmed/26612392">their academic performance</a> <a href="http://conservancy.umn.edu/handle/11299/162769">improves</a> significantly with later start time.</p>
<p>The Edina (Minnesota) School District superintendent and school board <a href="http://conservancy.umn.edu/handle/11299/139295">was the first district in the country</a> to make the change. The decision was a result of a recommendation from the Minnesota Medical Association, back in 1996. </p>
<p><a href="http://conservancy.umn.edu/handle/11299/139295">Research showed</a> significant <a href="http://www.startschoollater.net/major-studies--other-resources.html">benefits for teens</a> from that school <a href="http://files.eric.ed.gov/fulltext/ED454291.pdf">as well as others</a> with later start times. </p>
<p>For example, the crash rate for <a href="http://conservancy.umn.edu/handle/11299/162769">teens in Jackson Hole, Wyoming</a> in 2013 dropped by 70 percent in the first year after the district adopted a later high school start. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/138321/original/image-20160919-11095-1kl7moc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/138321/original/image-20160919-11095-1kl7moc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/138321/original/image-20160919-11095-1kl7moc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/138321/original/image-20160919-11095-1kl7moc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/138321/original/image-20160919-11095-1kl7moc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/138321/original/image-20160919-11095-1kl7moc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/138321/original/image-20160919-11095-1kl7moc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Schools that have made a change have found a difference.</span>
<span class="attribution"><a class="source" href="http://www.shutterstock.com/pic-200190794/stock-photo-back-view-of-a-group-of-high-school-students-walking-down-the-hallway-and-talking.html?src=9N4bTw-KMraeQCcS4voyrQ-1-32">Teenager image via www.shutterstock.com</a></span>
</figcaption>
</figure>
<p>At this point, <a href="http://www.startschoollater.net/">hundreds of schools across the country</a> in 44 states have been able to make the shift. The <a href="https://sleepfoundation.org/search/node/teen%20sleep">National Sleep Foundation</a> had a count of over 250 high schools having made a change to a later start as early as 2007.</p>
<p>Furthermore, since 2014, major national health organizations have taken a policy stand to support the implementation of later starting time for high school. The <a href="https://www.aap.org/en-us/about-the-aap/aap-press-room/pages/let-them-sleep-aap-recommends-delaying-start-times-of-middle-and-high-schools-to-combat-teen-sleep-deprivation.aspx?nfstatus=401&nftoken=00000000-0000-0000-0000-000000000000&nfstatusdescription=ERROR%3a+No+local+token">American Academy of Pediatrics</a>, the <a href="http://www.ama-assn.org/ama/pub/news/news/2016/2016-06-14-ama-supports-delayed-school-times.page">American Medical Association</a> and the <a href="http://www.cdc.gov/media/releases/2015/p0806-school-sleep.html">Centers for Disease Control and Prevention</a> have all come out with <a href="http://www.startschoollater.net/position-statements.html">statements that support</a> the starting time of high schools to be 8:30 a.m. or later. </p>
<h2>Challenges and benefits</h2>
<p>However, there are many schools and districts across the U.S. that are <a href="http://www.mlive.com/news/muskegon/index.ssf/2011/12/why_do_high_school_kids_go_to.html">resisting delaying the starting time</a> of their high schools. There are <a href="http://www.csun.edu/%7Eamg69708/prickly_politics.pdf">many reasons</a>.</p>
<p><a href="http://edr.sagepub.com/content/40/2/56.short">Issues</a> such as changing transportation routes and altering the timing for other grade levels often head the list of factors making the later start difficult. Schools are also concerned about <a href="http://www.aasa.org/content.aspx?id=36418">afterschool sports and activities</a>. </p>
<p>Such concerns are valid. However, there could be creative ways of finding solutions. We already know that <a href="http://www.aasa.org/content.aspx?id=36907">schools that were able to make the change</a> found solutions that show “out of the box” thinking. For example, schools adopted <a href="http://www.aasa.org/content.aspx?id=36418">mixed-age busing</a>, coordinated with public transport systems and expanded afterschool child care.</p>
<p>I do understand that there are other realistic concerns that need to be addressed in making the change. But, in the end, communities that value maximum development for all of its children would also be willing to grapple with solutions. </p>
<p>After all, our children’s ability to move into healthy adult lives tomorrow depends on what we as adults are deciding for them today.</p><img src="https://counter.theconversation.com/content/65308/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kyla Wahlstrom received funding from the CDC (2010-2013) to conduct longitudinal research on the outcomes for teens in high schools with later starting time. </span></em></p>Sleep deprivation in teenagers as a result of early morning school starts has been a topic of much debate. There’s more to this issue than just laziness.Kyla Wahlstrom, Senior Research Fellow in Organizational Leadership, Policy and Development, University of MinnesotaLicensed as Creative Commons – attribution, no derivatives.