We’ve all heard the term “addictive personality” used to describe that compulsion for chocolate, alcohol or even binge-watching a TV series.
Officially, psychiatry doesn’t recognise the term as a formal diagnosis. But there is clearly a difference between the way people manage their relationship with drugs, gambling and other potentially addictive behaviours. Some can take it or leave it, while others have less control over how much time and energy they spend on an activity or substance.
It’s this difference that’s fascinating to unpick. It reveals why some people are seemingly unable to control their drug use while others can. Even drugs like heroin or crack cocaine that we think of as highly addictive don’t render every user as a slave to repeated use. Conscripted American soldiers in Vietnam used heroin for months during the war but most were able to stop using the drug when they returned home. Although this is an unusual situation, it does suggest that addiction is about much more than just the chemical.
So, what is it that compels one person who tries a drug like heroin to want to use it again and another not to bother? It would be tempting, although somewhat damning, to think it was simply down to genetics. Research supports this idea but at best only accounts for 50 per cent of the potential risk of addiction. In other words, if your parents had an addiction there is a one in two chance you will.
Like many aspects of genetics, this has an obvious flaw. We are more than just a skeleton filled with genes. The way our parents or those around us behave influences what we do. If we learn that the way to control anger, low mood or anxiety is by having a drink then there’s a good chance we’ll replicate that behaviour.
This interaction between nature and nurture is where the science is at right now. The good news is that addiction isn’t entirely predetermined by genes. The bad news is that a combination of inheritance and how you grow up does increase the risk of developing unhealthy habits, whether that’s with drugs, sex or food. Experiencing trauma such as emotional, psychological or sexual abuse is the common thread of people who develop drug dependence, but it by no means explains everyone’s route into addiction.
Critically, it’s that first experience with a substance that can produce a feeling people have rarely if ever have felt. Warmth, contentment or even excitement are all common features reported by those who go onto use again and again. This is when free will or choice is so severely compromised that it, in effect, vanishes. To the onlooker, this appears to be self-destructive but paradoxically the person repeating this pattern is trying to maintain psychological survival.
Gender also plays a role. Men are typically attracted to risk, whereas women are often trying to treat a pre-existing psychological issue. That’s why men are over seven times more likely than women to be addicted to gambling. For drugs, the amount of time between the first use of a drug to the development of a problem is much shorter for women than men. An example of a clear gender difference but also one that we still don’t have enough evidence to explain.
This isn’t about personality traits such as being an introvert or extrovert; these characteristics are present whether you have an addiction or not. What seems to load the dice is previous life experience. Even then, that doesn’t explain everyone’s destiny.
There’s still so much we don’t know about why some people exhibit these compulsive behaviours and what maintains them. What we do know is that there is no “type” of person that develops an addiction, they are as varied as the human characteristics that distinguish us from one another, reassuring and humbling in equal measure.
Ian Hamilton lectures in mental health at the Department of Health Sciences, University of York