SAYING NO TO DRUGS CAN BE HARD, ESPECIALLY WHEN OUR BRAINS HAVE EVOLVED TO SAY 'WHY NOT?'

The Stoptober’ push to quit smoking is useful, but we need to look at why people start... especially when it's harder drugs

- DR DEAN BURNETT

The modern world is awash with information about the dangers of so-called recreational drugs, yet drug-taking remains a problem. Why do so many people choose to put unfamiliar chemicals into their bodies, despite being told repeatedly that it's a bad idea? What compels us to take drugs at all? There are many factors to consider when answering this question, the first of which can be categorised as biological.

Staunchly anti-drug types may insist that taking drugs is unnatural. Evidence suggests otherwise, however, because it seems that taking drugs is something our brains evolved to do.

Think about it: why would chemicals completely foreign to our biology interact with our brains at all, let alone so potently? And how would our bodies know how to break them down and flush them out? This suggests that our neurology and metabolism have been encountering drugs for long enough to evolve specific biological mechanisms for dealing with them.

It's believed that our pre-human ancestors regularly ate psychotropic or 'drug'-containing plants and gained survival advantages from them (such as more energy for hunting after consuming coca-like stimulants). Hence our brains and bodies evolved to take greater advantage of them. Accordingly, modern brains respond 'enthusiastically' to drugs.