Intelligent children are more likely than their less intelligent peers to use illegal drugs in later life, according to a study which has found a link between high IQ scores and drug use.
Children who were in the top third in terms of IQ when aged 5 and 10 were found to be at significantly increased risk of taking illegal drugs such as cannabis and cocaine when they became older.
The study was based on interviews with nearly 8000 people who were part of the 1970 British Cohort Study, which involved measuring IQ scores when each child was 5 and 10, and asking them about their drug habits when they were 16 and 30.
By the age of 30, around one in three men (35.4 per cent) and one in six women (15.9 per cent) had used cannabis while 8.6 per cent of men and 3.6 per cent of women had used cocaine in the previous 12 months, the study found.
A similar pattern was found for other drugs, such as barbiturates, LSD and heroin. Boys in the top third in terms of IQ when aged 5 were about 50 per cent more likely than the bottom third to have used drugs such as amphetamines and Ecstasy when aged 30.
