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Ice age: who has used crystal meth – and why?

After long periods of regular use, changes to the dopamine system can mean users appear flat and unmotivated. Shutterstock

If you’ve listened to the news lately, you might think that Australia is overrun with uncontrollably violent people on crystal methamphetamine. This may be true of those in crisis, but the bigger picture of meth use is much more varied.

Australia has one of the highest rates of illicit methamphetamine use in the world and the highest use among developed nations. Around 2.5% of Australians over 14 years (around half a million people) have used methamphetamine over the past year, compared with around 9% who have used cannabis and more than 4% who have used ecstasy.

Methamphetamine comes in a number of forms, mainly powder/pills (speed), crystal methamphetamine (crystal meth or ice) and a sticky paste (base).

The majority of users favour the lower-potency powder or pill form, which can be swallowed, snorted or injected; a smaller proportion use the crystalline form, which is usually injected or smoked. All forms of methamphetamine have a similar chemical makeup but crystal meth is much more potent.

Who uses meth?

Users of methamphetamine come from across the spectrum of society but a number of groups have higher than average rates of use. Very few people under the age of 20 use the drug, but those aged between 20 and 29 years have the highest rates of use at around 6%, though this actually decreased from 7.3% between 2007 and 2010.

As with most illicit drugs, men tend to use at higher rates than women and those in paid employment tend to use at higher rates than those not in paid employment. This may surprise some people, because of the unhelpful stereotypes that are perpetuated of the “down and out” illicit drug user.

However, the majority of people who use illicit drugs do not use regularly or in large quantities. A relatively small proportion (for methamphetamine, around 10-15%) of users go on to become dependent and need treatment.

Around 2.5% of Australian’s over 14 years have used methamphetamine in the last 12 months. Shutterstock

Some industry groups have higher than average use as well. These include hospitality (6.1%), construction (5.5%), media and telecommunications (5%), mining (4.4%) and finance (4.0%). Gay men and men who have sex with men are also reported to have a higher-than-average rate of use, as are sex workers.

There have been recent reports of increases in use of crystal methamphetamine, but it is unclear whether existing users are switching to the more potent form or new users are taking up the drug.

Short-term highs

Methamphetamine dramatically increases the level of dopamine, which regulates many systems in the brain, including feeling pleasure, motor control and cognitive processes such as attention and working memory.

Dopamine is released any time we do something that feels good, but methamphetamine makes the brain release up to 1,000 times the normal level of dopamine. Very little else, including other drugs, releases so much dopamine, and over such a long period of time, as methamphetamine.

With short term use, the brain’s dopamine reserves are emptied, and users of methamphetamine may feel tired and irritable for a few days while the stores build up again.

Long-term lows

After regular use, the brain’s dopamine system effectively wears out, and over time the brain stops being able to produce enough dopamine on its own.

When a person stops after a long period of use, they may feel depressed and lack motivation because they are unable to produce any more dopamine – at least for a while. They may also have strong cravings for sugary or starchy food because they are unable to get pleasure from anything else.

Meth changes the brain and, consequently, behaviour.

Methamphetamine also releases high doses of another brain chemical, noradrenaline, activating the “fight or flight” system. People using high doses can be anxious, jumpy and hypervigilant (flight) or suspicious and aggressive (fight).

Other effects occur in the frontal area of the brain that controls thinking, planning and decision-making, personality and appropriate social behaviour. The prefrontal cortex takes the information from the emotional centre of the brain and decides whether to act on it or not.

By disrupting dopamine activity, methamphetamine reduces the influence of the thinking parts of the brain, enabling the emotional parts of the brain to go unchecked.

Road to recovery

As a result of the effect of these chemicals on the brain when intoxicated on methamphetamine, users can be anxious, hypervigilant, aggressive and show signs of psychosis.

If someone is intoxicated on methamphetamine, telling them to calm down, or trying to restrain them is not a good idea – they may be scared and paranoid because of the drug effects. Try to calmly get them to a quiet place with reduced stimuli, but don’t put yourself in danger.

After long periods of regular use, changes to the dopamine system can mean users appear flat, unmotivated, and have such strong cravings that relapse is hard to avoid.

Understanding that the recovery process may be long and difficult because of these brain changes can assist long-term users to stick to their treatment program and can assist their family and friends to be patient.

Although the brain eventually recovers, these brain changes can last for months or years after stopping use, which is one of the reasons that recovery can take a long time, with many relapses along the way. It can take 12 months or more for a methamphetamine user to start to feel “normal” again.

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