Cognitive Abilities and Educational Attainment as Antecedents of Mental Disorders: A Total Population Study of Males.

The positive relation between mental health and educational attainment is well established, yet the extent to which cognitive abilities influence this gradient or independently predict mental health outcomes remains unclear. In this study, we investigated the association between adolescent cognitive abilities, educational attainment, and adult mental health. Cognitive ability was ascertained in Norwegian military conscript test data (N = 272,351; mean age 17.8 years; males only), whereas mental disorders were ascertained using the Norwegian register of primary care diagnoses received between the age of 36-40. Higher cognitive abilities were associated with a monotonically decreasing risk of developing all the studied mental disorders except bipolar disorder. The association held even when comparing the cognitive abilities of brothers raised in the same family, attesting that cognitive ability and mental disorders are not associated because both arise from the same family background circumstances. Similarly, individuals with higher educational attainment had fewer mental health disorders. The association between low cognitive abilities and the risk of mental disorders was notably stronger in males with low educational attainment, compared to those with high educational attainment. These individuals may be an underutilized target group for mental-disorder prevention.