High IQ in Childhood Associated with Later Illicit Drug Use

Parents of children who are labeled as gifted may, in some ways, feel that they have a bit of insurance against later problems. The children may not struggle with understanding concepts in ways that other children could, and with the addition of hard work, they may excel academically.

However, a new study finds reason for parents of above average kids to be on guard for other potential problems. While some parents might be tempted to assume that all is well when a report card reflects academic excellence, the study says that these kids might have a greater likelihood than their peers to experiment with illicit drugs.

The study, published in the online version of the Journal of Epidemiology and Community Health, provided evidence that kids with higher IQs, and especially girls with high IQs, may have a greater likelihood to try substances like marijuana and cocaine when they get older.

The study involved nearly 8,000 participants, of whom some were identified through testing as having a high IQ at the age of 5 and again at age 10. Those who had a high IQ had a greater likelihood of using certain drugs at the age of 16 and also when tested once again at the age of 30.

The researchers are not sure why the association exists, but they have developed a theory to explain it. Study researcher James White, PhD, said that the study authors believe that it could be tied to an increased willingness to try new things that is found among people that have a higher IQ. They are generally more receptive to fresh experiences, which may include illicit drugs.

White is a research associate at the Center for Development and Evaluation of Complex Interventions for Public Health Improvement, a part of Cardiff University in Wales.

The study’s findings are not consistent with many previous studies that have found an association between higher IQ and healthier behaviors, such as physically active, eating a nutritious diet and not using tobacco. Other studies, however, have shown that a high IQ in childhood is connected to alcohol disorders.

The study found that women identified as having a high IQ at the age of 5 had more than double the increased risk of using cocaine and marijuana before the age of 30 when compared with peers with a lower IQ at the age of 5.

Men had a greater likelihood of having used drugs if they had a higher IQ, by a rate of about 50 percent. Men were also 57 percent likelier to have tried numerous illicit drugs before the age of 30.

The findings for both men and women were consistent for those who had high IQ test scores at the age of 10. The results were consistent with controls for parents’ social status, adult socioeconomic status, and levels of psychological distress during adolescence.