Gambling is an activity in which participants wager something of value on the outcome of an event – for example a football match, or a scratchcard. The winnings can range from a small amount of money to a life-changing jackpot. The odds of winning are set by the betting company – for example, 5/1 or 2/1 – and matched to a choice the participant makes. It is possible to become addicted to gambling, just as it is to some drugs. Evidence suggests that people with genetic predisposition to thrill-seeking behaviour and impulsiveness can be particularly vulnerable.

Problem gamblers often find it hard to admit that they have a problem, and may hide their gambling habits from family and friends or lie about how much time or money they are spending on gambling. They can also be particularly vulnerable to financial crises, for example if they are paying off debt with their gambling income. If you are worried about how much you are gambling or if your gambling is causing harm to your health and wellbeing, seek help now.

In recent years, research has shown that there are many similarities between pathological gambling and substance-related disorders in clinical expression, brain origin, comorbidity and treatment response. This has led to the reclassification of pathological gambling as a behavioral addiction in DSM-5. This article reviews the theoretic and empirical work that has informed this decision. Longitudinal studies are especially important for understanding the emergence and maintenance of both normative and problem gambling behaviour.