AIMS: Mental health problems in young people are associated with educational outcomes. There are persistent difficulties in screening for these problems and mapping the trajectories of mental health in relation to academic and work outcomes. We investigated whether Strength and Difficulties Questionnaire (SDQ) scores in adolescents attending school were associated with school dropout in upper secondary school, both in adolescents with already recognised mental disorders and adolescents without known mental disorders.

METHODS: The data consisted of a questionnaire targeting 13,100 adolescents attending the final year of compulsory school combined with data derived from a national register. SDQ scores were divided into normal, borderline and abnormal scores. School dropout in upper secondary school was identified during a 2.5-years follow-up period. We stratified the data by recognised mental disorders. Logistic regression was performed to examine the association between SDQ scores and later school dropout with adjustment for parents' mental disorders, parents' educational level, sex, suicidal thoughts, school absence and negative childhood events.

RESULTS: During follow-up, 18.5% of adolescents experienced school dropout. Adolescents with abnormally high SDQ scores and borderline SDQ scores had higher odds for school dropout than adolescents with SDQ scores in the normal range. The association remained in the adjusted analysis, although more covariates showed independent contributions in association with school dropout.

CONCLUSIONS: Self-reported SDQ scores in adolescents attending school were associated with later school dropout irrespective of recognised mental disorders, indicating that markers such as the SDQ might contribute to the identification of vulnerable adolescent groups, although the findings of multifactorial contributions suggest we should consider more indicators in a risk assessment for school dropout.