By guest blogger Simon Oxenham

Academically successful children are more likely to drink alcohol and smoke cannabis in their teenage years than their less academic peers. That’s according to a study of over 6000 young people in England published recently in BMJ Open by researchers at UCL. While the results may sound surprising, they shouldn’t be. The finding is in fact consistent with earlier research that showed a relationship between higher childhood IQ and the use in adolescence of a wide range of illegal drugs.

James Williams and Gareth Hagger-Johnson categorised their participants as high or low academic achievers based on their record at age 11 in English, Maths and Science. Once in their teens, the high ability participants were more than twice as likely to regularly drink alcohol, but less likely to smoke cigarettes or engage in hazardous consumption of alcohol, defined as reporting being drunk more than 52 times per year. The higher ability students also smoked cannabis more during late adolescence, both regular and occasional use; the likelihood that their use would continue persistently was nearly double that of their lower ability peers.

These new results jibe with evidence from the 1970 British Cohort Study which has followed over 16,000 babies born in April 1970 from birth to the present day. An analysis published in 2011 of eligible members of this cohort found that high IQ scores at ten years of age were linked to cannabis use at 16 years of age as well as cannabis, cocaine, amphetamine and ecstasy use at 30 years of age. This pattern held after taking account of parents’ social class, income and education and children’s levels of psychological distress during adolescence and their later adult socioeconomic advantage, though it’s difficult to rule out the role these factors may have played.

These studies only show correlations and they don’t tell us why the patterns exist. One possible explanation is that intelligent children have an increased desire for novelty and stimulation. Intelligence has long been known to correlate with openness to new experiences, it could well be that the same forces that motivate intelligent people to learn about their environment also motivate them to use drugs. But the fact that the academic ability/ drug-taking relationship in the new BMJ Open study was strongest for persistent use of alcohol and cannabis would suggest that this is not simply down to intelligent children having a tendency towards a short period of “experimentation”.

An alternative explanation put forward by the researchers behind the 2011 cohort study is that intelligent children often feel stigmatised by their peers. Perhaps higher levels of drug and alcohol use could be a coping strategy to being bullied or ostracised. Conversely, perhaps intelligent children are in fact more socially adept and therefore more likely to be accepted by older children, resulting in increased access to drugs and alcohol.

Yet another explanation is that intelligent and well-educated children and adults may be more likely to recognise that the risks of consuming drugs and alcohol are often widely overstated. Several studies have found very high levels of drug use among doctors and medical students, who should have a far better understanding of the true risks of using drugs than the wider population.

It’s also possible that children see through more simplistic attempts to dissuade them from consuming drugs and alcohol and it is perhaps fair to assume that this effect would be stronger for more intelligent and better educated children. Several studies of alcohol and drug education programs in the United States have found these schemes to have no effect. One carefully controlled longitudinal study even found a harmful effect of the Drug Abuse Resistance Education (D.A.R.E.) programme, famed for popularising the “Just Say No” mantra – children in suburban schools who received the programme subsequently showed increased levels of drug use.

The new research adds further weight to the argument that drug education programmes would likely be more beneficial if they were more educational and evidence-based. This could include an emphasis on the increased risks to developing brains from consuming drugs and alcohol at an early age, and advice focused on harm-reduction so that young people who do choose to use drugs are better equipped to do so safely.

A better metric for the success of drug education strategies may be the rate of harm caused as a result of drug and alcohol use. While drug use in the UK has fallen over recent years, numbers of drug deaths have risen, heavily driven by opiate deaths. The combined evidence suggests a need to take a step back and assess the effectiveness, long term impacts and possible unintended side effects of existing strategies to guide children’s choices.

—Childhood academic ability in relation to cigarette, alcohol and cannabis use from adolescence into early adulthood: Longitudinal Study of Young People in England (LSYPE)

Post written by Simon Oxenham for the BPS Research Digest. Simon covers psychology and neuroscience critically in his Brain Scanner column at New Scientist. Follow @simoxenham on Twitter, Facebook and Google+, RSS or on his mailing list.