Association between school achievement in upper secondary education and subsequent risk of mental disorders: a population-based cohort study.

BACKGROUND

Poor school achievement in comprehensive education (~ age 15) has been associated with the later risk of mental disorders, but it remains unclear whether school achievement in upper secondary education (~ age 18) is also associated with this risk. We examined whether school achievement in upper secondary education is associated with the later risk of mental disorders and whether school achievement in comprehensive education modifies these associations.

METHODS

We studied all individuals born in Finland between 1980 and 2001 (N = 579 781). Individuals were followed from graduation from upper secondary education (ages 18-20) until first mental disorder diagnosis, emigration, death, or December 31, 2023. Matriculation examination grade point average (GPA) at the end of upper secondary education was the main exposure. Time to a mental disorder diagnosis was the outcome. Associations were estimated using Cox proportional hazards models, including sibling-stratified analyses and stratification across comprehensive education GPA groups.

RESULTS

Upper secondary GPA showed no consistent association with any mental disorder diagnosis as a broad category. Greater upper secondary GPA was generally associated with smaller risk of substance use disorders and greater risk of depression, anxiety, eating, and personality disorders. Reduction in GPA from comprehensive to upper secondary education was associated with greater risk of schizophrenia, and improvement with greater risk of bipolar disorder.

CONCLUSIONS

Associations between school achievement in upper secondary education and later mental disorders are disorder-specific, with higher school achievement associated with either an increased or decreased risk depending on the specific disorder.