Good school performance is a risk factor of suicide in psychoses:: a 35-year follow up of the Northern Finland 1966 Birth Cohort

Objective: Our aim was to analyse the relationship between good school performance and risk of suicide in the Northern Finland 1966 Birth Cohort, especially in psychoses. Method: A total of 11 017 cohort members who were alive at the age of 16 years were followed up to the age of 35 years. School performance was measured by the school marks given at age 16 at the end of comprehensive school. School, diagnostic and mortality data were based on national registers. Results: For psychotic persons having good school performance (highest 20%), the adjusted hazard ratio (HR) for suicide was 3.56 (0.97-13.05) compared with the remaining 80%. In the non-psychotic population (97% without psychiatric hospitalization), accordingly, adjusted HR was 0.28 (0.07-1.16). Interaction (school performance x psychiatric diagnosis) was significant (P = 0.01) even when adjusted with gender, social class and age of onset of illness. Conclusion: Good school performance at age 16 years is associated with increased risk of suicide (before age 35 years) in persons who develop psychosis, whereas in persons who do not develop psychosis, it is associated with lower suicide risk.