A 2011 study that was published in the Journal of Epidemiology and Community Health found that there is a link between having a high IQ and the use of illegal drugs. The study’s findings show that people with a high IQ as a child are more likely to use illegal drugs as young adults.
After analyzing data provided by roughly 8,000 people from the British Cohort Study, researchers found that men with high IQ scores at the age of 5 were around 50 percent more likely to go on to use illegal drugs such as ecstasy and marijuana. Women with high IQs were nearly twice as likely to use illegal drugs compared to those with lower IQs, The Weed Blog reported.
Here’s the abstract of the study:
Background: Recent reports have linked high childhood IQ scores with excess alcohol intake and alcohol dependency in adult life, but the relationship with illegal drug use in later life is relatively unknown.
Methods: The authors used data from a large population-based birth cohort (1970 British Cohort Study) with measures of lifetime cannabis and cocaine use, parental social class and psychological distress at 16 years; cannabis, cocaine, amphetamine, ecstasy and polydrug use (more than three drugs) in the past 12 months; and social class, educational attainment and gross monthly income at 30 years. All members of the cohort with IQ scores at 5 or 10 years were eligible to be included in the analyses.
Results: Of the 11 603 (at 5 years) and 11 397 (at 10 years) cohort members eligible, 7904 (68.1%) and 7946 (69.7%) were included in the analyses. IQ scores at 5 years were positively associated with cannabis (OR (bottom vs top tertile) =2.25, 95% CI 1.71 to 2.97) and cocaine use (OR 2.35, 95% CI 1.41 to 3.92) in women and with amphetamines (OR 1.46, 95% CI 1.03 to 2.06), ecstasy (OR 1.65, 95% CI 1.15 to 2.36) and polydrug use (OR 1.57, 95% CI 1.09 to 2.26) in men at 30 years. IQ scores at 10 years were positively associated with cannabis, cocaine (only at 30 years), ecstasy, amphetamine and polydrug use. Associations were stronger in women than in men and were independent from psychological distress in adolescence and life-course socioeconomic position.
Conclusion: High childhood IQ may increase the risk of illegal drug use in adolescence and adulthood.