|Clever children more likely to use drugs|
A new study suggests children with high IQ have a higher rate of illicit drug use than their peers. There is little previous research on this issue and that which has been done has given conflicting results. The higher rate of drug use is considered surprising by some as those with high IQ typically engage in more healthy behaviour such as healthy eating and avoiding smoking. This is considered to be because those with higher IQ make themselves better informed about risks and benefits of different behaviours. This study drew on data from the British Cohort Survey which follows 20,000 individuals who were born in the same week in 1970. Subjects are surveyed at 5 to 10 year intervals which allows longitudinal analysis to be performed. This means that variables can be followed on the same individuals over time in contrast to a cross sectional study where the whole population is compared at a particular point in time. The authors of the study found that high IQ in childhood was associated with higher use of most illicit drugs. High IQ is known to be linked to socio-economic position as well as psychological distress. These factors themselves are linked to drug use and could explain the link with IQ. However, the authors found that even when they accounted for these factors the link remained. Some previous studies had suggested that high IQ was linked to drug use in adolescence, but not later life. These studies were limited due to their small size and focus on certain demographics groups. This study measure IQ at age 5 and drug use at ages 16 and 30. Drug use between these years were not measured so people who only used drugs between these ages would not have picked up by this study. The results were similar for most drugs. The authors speculate that the increased rate of drug use could be a result of boredom or stigmatisation among more intelligent children, although they did not provide a strong explanation for the link.
NHS Behind the Headlines: http://www.nhs.uk/news/2011/11November/Pages/intelligent-children-illegal-drug-use.aspx
Press release in BMJ: http://group.bmj.com/group/media/latest-news/high-childhood-iq-linked-to-subsequent-illicit-drug-use
Paper in BMJ: http://jech.bmj.com/content/early/2011/10/28/jech-2011-200252.abstract