A roulette wheel

Double or quits?

Compulsive gambling has been studied more extensively than other non-drug addictions

Statistics for gambling, including problem gambling, are not always reliable, and are hard to compare between countries and studies. There is good evidence that more than three-quarters of the UK population gamble, if only by joining in the National Lottery.

Gambling – including betting on horses, internet gambling, poker, slot machines and the Lottery – has increased in recent years, with the British Gambling Prevalence Survey from the Gambling Commission reporting that the number of adults participating in some form of gambling had risen 8 per cent between 2007 and 2010. There was also an increase in the number of ‘problem gamblers’, up to 0.9 per cent from 0.6 per cent, and these individuals were more likely to be male, to be younger, and to have parents who regularly gambled.

Why is gambling addictive?

Professor Mark Griffiths of Nottingham Trent University suggests that problem gamblers suffer a bias in perception, reading losses as ‘near misses’. This is especially powerful when using slot machines, where the player can go again in seconds, and see if they can convert the near miss into a win. Nowadays, internet gambling can have the same effect. Slot machines – fruit machines are the most common example – are also made so that the player feels they are using some skill, and problem gamblers are prone to exaggerate the influence they can have on the results. Online games may use music and visual effects that encourage faster playing.

Recent research has highlighted the involvement of this ‘near miss’ psychology, using fMRI scanning technology to show that near-miss outcomes were associated with responses in the ventral striatum, an area involved in the dopamine reward pathway. Moreover, gambling severity (how often the individuals participated in gambling activities) was associated with these responses.

Who’s at risk?

A twin study in the USA published in 2010 suggested that genetic factors account for around 70 per cent of the variance in gambling. However, in line with some other studies, there were significant differences between men and women. For males there was 85 per cent genetic influence on gambling. For females, no genetic influence was measured – the differences between those in this group were all due to environmental factors.

Between 2007 and 2010, the Gambling Prevalence Survey found a bigger increase in online gambling among women than among men, potentially due to the increase in gambling sites that are more ‘female-oriented’. Individuals that register high on tests for novelty-seeking and impulsiveness are more likely to engage in, and potentially become addicted to, gambling.

Negative effects of problem gambling

The main negative effects of problem gambling come from the sheer amount of time it takes up – all day, every day in the worst cases. This undermines family relationships and social life, and causes trouble with employers. There is also a high risk of running up big debts, which gamblers often keep hidden from their friends and family. This can cause a number of problems: gamblers often experience mood swings, and may be prone to depression.

Any similarities to substance dependency?

There is experimental evidence of tolerance. New gamblers’ pulse rates rise when they are playing; seasoned gamblers also feel such a rise, but it soon slows down again. They may place bigger bets or play faster to get the same effect as before. Gamblers may also show heightened responses to images of gambling on EEG brain scans – similar to the enhanced response drug addicts show to images of drug paraphernalia.

Lead image:

GregMontani/Pixabay CC BY


About this resource

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

Education levels:
16–19, Continuing professional development