High IQ in childhood linked to later illegal drug use
By Liz Lockhart
Research suggests that a high childhood IQ may be linked to later life illegal drug use.
This British Cohort Study bases its findings on data from nearly 8,000 people in the 1970’s. It is a large, 
ongoing, population based study which looks at lifetime drug use, educational attainment and socioeconomic factors.
Researchers, using a validated scale, measured the IQ scores of the participants at the ages of 5 and 10 years. Information was collected on self-reported levels of psychological distress and drug use at the age of 16 and then, at the age of 30, for drug use only. Drug use included cannabis, heroin, LSD (acid), cocaine, uppers (speed) and downers (barbiturates, blues).
Just over one in three men (35.4%) and one in six women (15.9%) had used cannabis by the age of 30. 8.6% of men and 3.6% of women had used cocaine in the previous 12 month period. The pattern for the use of other drugs was found to be similar, with drug use being twice as common for men than for women.
The analysis showed that. 25 years later, when intelligence was factored in, men with high IQ scores at the age of 5 were about 50% more likely to have used ecstasy, amphetamines and several other illicit drugs than those will low scores.
Among women the link was even stronger. High IQ women were more than twice as likely to have used cannabis and cocaine as those with low IQ scores.
By the age of 30, the same associations emerged between high IQ at the age of 10 and subsequent use of cannabis, amphetamines, ecstasy, cocaine and multiple drug use.
Irrespective of anxiety and depression during adolescence, parental social class and lifetime household income, the findings remained the same.
‘Although most studies have suggested that higher child or adolescent IQ prompts the adoption of a healthy lifestyle as an adult, other studies have lined higher childhood IQ scores to excess alcohol intake and alcohol dependency in adulthood,’ say the authors.
The link between high IQ and illicit is not yet clear but the authors point to previous research which shows that highly intelligent people are open to experiences and keen to experience stimulation and something new.
The authors explain ‘Other research has also shown that brainy children are often easily bored and suffer at the hands of their peers for being different. Either of which could conceivably increase vulnerability to using drugs as an avoidant coping strategy.’
