If somebody asked you which drugs you take regularly, you might not think of mentioning the caffeine in your morning cup of coffee. Yet caffeine, which 90% of adults in the US consume regularly in coffee, tea and energy drinks, is a psychoactive drug – in other words, it passes through the blood-brain barrier and affects brain function.
Caffeine is a stimulant, which is why it makes you feel more awake. However, along with this apparently useful effect, caffeine may also lead to greater impulsivity or risk-taking behaviours. Researchers at the University of Cambridge have become interested in how caffeine consumption is linked to one particularly type of impulsive behaviour: problem gambling.
In a study published recently in Addictive Behaviours, Dr Samuel Chamberlain from Cambridge’s Department of Psychiatry and Professor Jon Grant from the University of Chicago, studied caffeine consumption and impulsivity in 61 problem gamblers aged 18 to 29. Participants reported how much caffeine they consumed over the last month, and completed a series of cognitive tasks and questionnaires that measured impulsivity. Participants also competed the Cambridge Gambling Task, which measures the quality of decision making in gambling.
The research team ran a statistical model to look at which factors predicted the amount of caffeine that the participants consumed. The model showed that participants who consumed more caffeine were more impulsive and made more risky or irrational decisions in the Cambridge Gambling Task. Being older, starting gambling at a younger age and smoking were also related to greater caffeine consumption.These factors (impulsivity, gambling task performance, age, age at the start of gambling and nicotine use) combined explained 32% of variation in caffeine intake in this population of problem gamblers.
Problem gamblers in the study reported consuming more caffeine than people in the general population, suggesting a link between problem gambling and increased caffeine consumption. It was found that those gamblers who consumed more caffeine also consumed more nicotine. Given that nicotine is also a stimulant, this could mean that gambling is associated with a predisposition towards stimulant drug use.
This is the first study to report a link between caffeine consumption and impulsivity in problem gamblers. The study, as the authors acknowledge, cannot prove whether caffeine leads to gambling, or rather might be a form of coping in gamblers, perhaps to help them stay awake during prolonged gambling episodes. An alternative explanation for the association is that people who are more impulsive have a greater chance of becoming problem gamblers, and are more likely to consume more caffeine.
Future research will determine the direction of any causal relationships between impulsivity, problem gambling and caffeine intake. If impulsivity does increase caffeine intake and problem gambling behaviours, then neurocognitive tests of impulsivity may be a useful way of identifying those who are at risk for problem gambling. Alternatively, if excessive caffeine intake does lead to risky gambling behaviour, treatment for problem gambling could include controlling caffeine intake.
Dr Samuel Chamberlain said:
“Caffeine is one of the most widely used, socially acceptable drugs in the world. Yet, we know surprisingly little about its effects on brain chemistry, cognitive abilities, and psychiatric symptoms. Caffeine has potential beneficial effects for sustaining attention – for example, in students or taxi drivers. At the same time, it has a down-side in people with certain mental disorders, such as gambling disorder, or anxiety problems.”
Written by Sarah Griffiths