If you were brought up on the ‘just say no’ message of the 1980s, you probably soaked up beliefs around drugs being highly addictive and damaging for your brain. If you were exposed to hard drugs you could be hooked immediately. Remember the advert about your ‘brain on drugs’ sizzling like a fried egg? And the fault was placed squarely on the shoulders of these illegal and dangerous substances, which need to be banned to keep us from harm. 

This is understandable in many ways, as the deaths caused by drug use and addictions are clearly tragic, and illicit drug use is always dangerous. However, there are also some problems with this approach. If we understand that addictive behaviours follow similar processes no matter what the addiction, blaming drugs for drug addiction starts to get a little confusing. Is alcohol responsible for alcohol addiction? Food for binge eating and obesity? We have seen the consequences of alcohol prohibition, and we can’t ban food, so how do we align this with the messages we hear about drugs like crack cocaine and heroin being so irresistible that if you have one hit you’ll be hooked? 

The theories about drugs being helplessly addictive came from studies on laboratory animals, who were found to self-administer drugs like morphine, heroin and cocaine incessantly under certain conditions, in some cases neglecting food and water until they died. Professor Bruce Alexander noticed that the rats in question were caged and isolated, and questioned the interpretation of these earlier studies. In 1977 he pulled together a team of researchers, and rather than housing the lab rats in the small and bleak cages of the earlier experiments, built ‘colony housing’, which included cedar shavings, other rats and lots of nooks and crannies for hiding, nesting and having some rat fun. They called it ‘Rat Park’. 

These studies showed that rats living in rich and social environments took less, or no drugs even when they were freely available. It wasn’t exposure to the drugs that led to compulsive consumption, but isolation and disconnection from a healthy and fulfilling social environment. Later studies have shown that cocaine-addicted rats will choose same sex snuggling over more cocaine, if they have the chance (Zernig, 2013). 

Humans, like rats, living fairly healthy and reasonably fulfilled lives also tend not to become addicted to drugs or other experiences. In fact, even with the substances that are generally seen as highly addictive, like heroin and crack cocaine, we know that just under 90% of people are able to use them without becoming addicted. Evidently, using drugs does not always lead to addiction, just as eating, having sex, putting a bet on and exercising do not always become compulsive. 

What makes it more likely that one person becomes addicted and another doesn’t? Addiction is something that develops from a particular combination of ingredients, to do with vulnerable individuals having significant experiences at particularly sensitive points in development, within a specific context that maintains it. Individual vulnerabilities are found in the relationships between our temperaments, or our genetic potential, the emotional and cultural environments we are born into, and what we make of them. And there are qualities of certain experiences that are more likely to hook us in, but they are far from the whole story.

It isn't so much that drugs aren't addictive, but that many things can be, given the right circumstances. 

This is an extract from The Psychology of Addiction, published by Routledge: