Mental health problems in the 10(th) grade and non-completion of upper secondary school: the mediating role of grades in a population-based longitudinal study

BACKGROUND: School drop-out is a problem all over the world with adverse life-course consequences. The aim of this paper is to study how internalising and externalising problems in the 10(th) grade are associated with non-completion of upper secondary school, and to examine the mediating role of grade points in the 10(th) grade across general academic and vocational tracks in upper secondary school. We also study the impact of health behaviour. METHODS: Population-based health surveys were linked with Norwegian registries on education and sociodemographic factors (n = 10 931). Mental health was assessed by the self-report Strengths and Difficulties Questionnaire. Logistic regression was used to analyse the relations between mental health and health behaviour in 10(th) grade and non-completion of upper secondary school. The mediating effect of grade points was studied by causal mediation analysis. RESULTS: Adolescents not completing upper secondary school reported more externalising problems and girls more internalising problems in the 10(th) grade, after adjustments. Smoking and physical inactivity increased the odds of non-completion of upper secondary school. Causal mediation analyses showed that a reduction in externalising problems of 10 percentage points led to lower rates of non-completion of 4–5 percentage points, and about three-quarters of this total effect was mediated by grades. For internalising problems the total effect was significant only for girls (1 percentage point), and the mediated effect of grades was about 30%. The effect of mental health problems on school dropout was mainly the same in both vocational and general tracks. CONCLUSIONS: Assuming a causal relationship from mental health problems to school performance, this study suggests that externalising problems impair educational attainment. A reduction of such problems may improve school performance, reduce school drop-out and reduce the adverse life-course consequences.