Why do some people get addicted to drugs and others don't?


Why do some people get addicted to drugs and others don't?

Addiction (or dependence) is often defined as continuing to use a substance even when its use is causing you harm. This use is usually compulsive, or difficult to control. Most people who use drugs don't become 'addicts' and understanding why some people do become addicted is complex. Are some people more predisposed to addiction or are societal or environmental factors to blame?

Some drugs are believed to be far more addictive than others (e.g., heroin and crack cocaine), but there are some people who use drugs like these who never become addicted. Others may use drugs that are not seen as so addictive (e.g., MDMA) and end up using in a seemingly addictive way. Increasingly we hear about people who are apparently 'addicted' to work, gambling, shopping and their smartphone and social media. What is similar about all these behaviours is that they can result in the person involved getting some sort of pleasurable effect and then a powerful urge to repeat the experience.

But why do some people get addicted and others don't? A combination of factors influences risk for addiction. The more risk factors a person has, the greater the risk of dependence. Some experts say that genetics play a big part while others believe that this factor has been exaggerated. We now know that abuse and trauma in childhood and mental illness in adolescence and adulthood can lead to more problematic drug use and, potentially, addiction.

In many developed countries addiction, as opposed to drug use, occurs in communities with greater social problems, such as poorer levels of education, limited employment, inadequate housing and support networks and a general feeling of despair and hopelessness.

The experience of US soldiers in the Vietnam War is a great example of how complex 'addiction' really is ... At the end of the war it is estimated that at least 20% of the returning troops were addicted to heroin. There was great concern about the impact this would have on the soldiers, their families and the wider community. In reality, 95% of the drug-dependent soldiers simply stopped using when they got home. A safe environment had replaced the terrifying threats associated with war.

This is a complex issue and one that many try to explain in a simplistic way, e.g., "They have an addictive personality". Some people may be more prone to addiction due to genetic reasons and there are of course some drugs that are far more likely to lead to greater problems in this area. We are learning more, however, that other social problems are also important factors that need to be considered, particularly when trying to prevent people from developing problems with their drug use.

First published: March 2019