Defining addiction

How do key health bodies define addiction?

If you do something pleasurable, the chances are that you’ll want to do it again. Do it a lot – whether it is eating a chocolate bar or watching a band on YouTube – and you have a habit. Most habits are pretty harmless. The worst thing likely to happen is that you waste time on them or people make fun of them. A few, though, turn into a problem.

Sometimes that problem is so serious we call it an addiction. The addictions with the tightest grip tend to involve drugs, sometimes illegal ones. But take a look in the papers: people who can’t get enough of sunbeds, shopping or sex are all addicts, journalists say. Are they really? What about those unable to control how much they gamble or play games online?

Deciding whether these really are addictions means having a clear definition of what addiction is. That is difficult, because addicts do not just feel one thing. Most definitions amount to a list of features, and people then discuss whether a particular behaviour can count as an addiction.

All the definitions agree that addiction involves psychological need: you really feel you cannot do without it. Then there is physical need: cutting off supply makes you ill. Tolerance is common: where you need more and more of the thing you are addicted to for the same effect. So is persistence: the fact that you’ll continue with a particular behaviour in spite of its harmful effects. Some addictions, especially to certain drugs, tick all of these boxes.

Other things that may be addictive, such as gambling, do not. In those cases, there is more of an overlap with obsessive or compulsive behaviour of other kinds. So addiction is complex, involving aspects of brain and body that are not well understood, along with social influences and personal history. That leaves plenty of room for disagreement among researchers and health workers about its diagnosis, causes, effects, treatment and prevention.

World Health Organization

The World Health Organization (WHO), the UN-backed body based in Geneva, prefers to talk about ‘dependence’ rather than addiction. For drugs, it uses this word to cover both the physical and psychological aspects of addiction, such as withdrawal symptoms and loss of control respectively.

Back in 1964, a WHO expert committee offered a definition of dependence that brought in aspects of behaviour, cognition and physiology. The latest WHO International Classification of Diseases says that dependence includes strong desire, problems controlling use, withdrawal symptoms, tolerance for increasing doses, ignoring alternatives, and continuing to use a drug in spite of the harm it causes.

American Psychiatric Association

The American Psychiatric Association (APA) has dropped the term ‘dependence’ and prefers the term ‘substance use’ (or ‘substance use disorder’), explaining that dependence should be used only to describe a precise physiological response to particular substances.

The APA’s recent Diagnostic and Statistical Manual (DSM) has also included gambling disorder within the ‘substance-related and addictive disorders’ section as the first (and only) ‘behavioural addiction’. The APA considers internet gaming disorder as an area warranting further research before deciding whether it too may join this behavioural addiction list.

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About this resource

This resource was first published in ‘Addiction’ in June 2010 and reviewed and updated in September 2015.

Education levels:
14–16, 16–19, Continuing professional development