Excellent school performance at age 16 and risk of adult bipolar disorder: national cohort study.

BACKGROUND Anecdotal and biographical reports suggest that bipolar disorder may be associated with high IQ or creativity, but evidence for any such connection is weak. AIMS To investigate possible associations between scholastic achievement and later bipolar disorder, using prospective data, in a whole-population cohort study. METHOD Using individual school grades from all individuals finishing compulsory schooling in Sweden between 1988 and 1997, we tested associations between scholastic achievement at age 15-16 and hospital admission for psychosis between ages 17 and 31, adjusting for potential confounders. RESULTS Individuals with excellent school performance had a nearly fourfold increased risk of later bipolar disorder compared with those with average grades (hazard ratio HR = 3.79, 95% CI 2.11-6.82). This association appeared to be confined to males. Students with the poorest grades were also at moderately increased risk of bipolar disorder (HR = 1.86, 95% CI 1.06-3.28). CONCLUSIONS These findings provide support for the hypothesis that exceptional intellectual ability is associated with bipolar disorder.