It’s normal to feel down in the dumps from time to time, so drawing a line between low moods and mental illness is understandably fraught.
But are health professionals treating normal sadness as a clinical disorder and over-prescribing antidepressants?
Or is depression a disease manufactured by Big Pharma to sell more antidepressants, as some have suggested?
The reality is depression can affect both mental and physical wellbeing. In extreme cases, depression can lead to suicide. So it’s no surprise many clinicians err on the side of caution when it comes to prescribing antidepressants.
Efficacy of antidepressants
Most antidepressants work by increasing neurotransmitters such as serotonin and noradrenaline in the brain.
For over 40 years, researchers have thought depression could be caused by a deficiency in one or more neurotransmitters. This hypothesis continues to stimulate scientific research, which is increasingly focusing on the contribution of genetic and environmental factors.
The most commonly-prescribed class of antidepressant – selective serotonin reuptake inhibitors (or SSRIs), such as Prozac – increase the amount of serotonin available to receptors in the brain.
Other commonly prescribed antidepressants – the serotonin and noradrenaline reuptake inhibitors (or SNRIs), such as Efexor increase both serotonin and noradrenaline.
Some have questioned the usefulness of all antidepressants, leading to media headlines declaring that “Antidepressants don’t work!”. But depression is a complex disorder and patients often need to try a number of antidepressants before finding one that works for them.
Antidepressants have a variety of side effects including reduced libido, agitation, weight gain and even suicidal ideation in children and adolescents.
“Modern” antidepressants such as Prozac or Efexor may have adverse cardiovascular effects although not to the same extent as the older-style “tricyclic” antidepressants, which are still prescribed for more severe cases of depression.
Medications to treat other health concerns are also being found to improve depressive symptoms. Professor Ian Hickie and Associate Professor Naomi Rogers from the University of Sydney and Central Queensland University, recently published a review article on novel antidepressant therapies in The Lancet medical journal.
They suggest that melatonin-based therapies such as agomelatine, usually used to treat sleep disorders, may have antidepressant effects and fewer side-effects than antidepressants, as well as improved sleep quality.
The link between mental and physical health
The brain has enjoyed a privileged status in psychology and psychiatry, in part due to recent scientific advances in neuroscience. But the heart also plays an important role in our emotional life.
We noted in our last Conversation article that people with depression are three to four times more likely to die of cardiovascular disease than those without depression, irrespective of a prior history of cardiovascular disease.
So if depression can break your heart, are antidepressants able to put it back together again? Our research shows that while they might reduce depressive symptoms, the answer is no.
Treatment with a variety of antidepressants may improve mental wellbeing but it doesn’t lower the risk of heart disease associated with depression. More concerning is new data indicating that antidepressants themselves may have adverse effects.
Depression and cardiovascular disease are forecast to be the two greatest burdens of disease by 2020 and the two are related, highlighting the urgent need for new treatments.
Hickie and Rogers’ review highlights the potential for novel antidepressant treatment with reduced side effects. Although further research is required, a relatively safe cardiovascular profile has been reported for these novel antidepressants.
Other treatment options
Other treatment options – especially for milder forms of depression – include exercise, meditation and cognitive behavioural therapy.
These non-pharmacological options are better tolerated by patients with depression, and have fewer side effects than antidepressant medication.
It’s also possible that these alternatives, particularly exercise, have cardio-protective effects which may help reduce the risk of cardiovascular disease.
A combination of antidepressant medication and psychological interventions may be beneficial for moderate or severe forms of depression.
Working out what’s best
It can be difficult to navigate competing messages from the media, family and friends, and even health professionals about the different pathways available for depression treatment.
If you are looking online for information, visit credible, evidence-based sites such as National Institute for Health and Clinical Excellence (NICE) and Beyond Blue.
Remember, it can take a fair bit of trial and error to work out which, if any antidepressant, is right for you. If you’re not happy with the advice you’re getting from your GP, psychologist or other health professional, why not seek a second opinion?
Are you confused about depression treatments? Leave your comments below