Mental disorders in childhood or adolescence and subsequent comprehensive school achievement

Childhood mental disorders are associated with poorer school achievement, with potential negative long-term socio-economic consequences, but few large-scale studies have examined this association, particularly the role of age at onset. Using a nationwide Finnish cohort, we examined the associations between mental disorders and school achievement, focusing on gender and age at onset.

This nationwide cohort study used data from Finnish national registers. The study population consisted of all individuals born between January 1, 1990, and December 31, 2003, who completed their comprehensive education in Finland during the years 2005 to 2019 (n = 837,546). The exposure was diagnosis of any mental disorder or specific mental disorders between the age of 1 year and graduation. School achievement was measured using the grade point average (GPA), a summative measure of performance across all subjects during the final three years of comprehensive school.

Of the total study population (411,054 females, 426,492 males), 137,427 (16.41%) were diagnosed with a mental disorder before completing comprehensive school. Students with a mental disorder had lower school achievement compared with their peers without a diagnosis, -0.41 [95% CI, -0.41 to -0.40]. The association was stronger for female students, -0.45 [95% CI, -0.46 to -0.45], than for male students, -0.37 [95% CI, -0.38 to -0.37]. Later-onset mental disorders were associated with poorer school achievement, a pattern observed across most specific mental disorders.

Childhood mental disorders are linked to lower school achievement, particularly among females and those diagnosed at a later age, underscoring the need for targeted psychological support for females and adolescents.