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.