Academics found that women who had high IQ scores in childhood were more likely to take illegal drugs when they are in their 30s.

INTELLIGENCE early on in life among women may be linked to drug-taking as they get older, Welsh researchers have discovered.

Academics found that women who had high IQ scores in childhood were more likely to take illegal drugs when they are in their 30s. One of the theories they give for being behind this is that those people with a high IQ are more willing to try new experiences.

Dr James White, who led the research, said: “Although most studies suggest that higher child or adolescent IQ prompts the adoption of a healthy lifestyle as an adult, other studies have linked higher childhood IQ scores to excess alcohol intake and alcohol dependency in adulthood.

“Although it is not yet clear exactly why there should be a link between high IQ and illicit drug use, previous research has shown that people with a high IQ are more open to new experiences and keen on novelty and stimulation.

“There is a clear need for future epidemiological and experimental studies to explore these and other pathways.”

The study, by the university’s Centre for the Development and Evaluation of Complex Interventions for Public Health Improvement (DECIPHer), examined data from just under 8,000 people in the 1970 British Cohort Study, which is a large ongoing population-based study, looking at drug use and other factors in society.

The IQ scores of the participants were measured at the ages of five and 10 years, using validated scales, and information was gathered on self reported levels of psychological distress and drug use at the age of 16, and again at the age of 30.

Drugs assessed at 16 included cannabis and cocaine; and at 30 years of age included cannabis; cocaine; amphetamines; and ecstasy.

By the age of 30, 35.4% of men and 15.9% of women had used cannabis, while 8.6% of men and 3.6% of women had used cocaine, in the previous 12 months.

A similar pattern of use was found for the other drugs, with overall drug use twice as common among men as among women.

Men with high IQ scores at the age of five were around 50% more likely to have used amphetamines, ecstasy, and several illicit drugs than those with low scores, 25 years later.

The link was even stronger among women, who were more than twice as likely to have used cannabis and cocaine as those with low IQ scores. The same associations emerged between a high IQ score at the age of 10 and subsequent use of cannabis, ecstasy, amphetamines, and cocaine, although this last was only evident at the age of 30.

Recognised risk factors for drug use, such as, levels of anxiety and depression during adolescence, parental social class, level of education, social class at 30 years and monthly income were all taken into account during analysis of the study’s findings.