After the Divorce: Academic Achievement, Mental Health, and Health Complaints in Adolescence : Heterogeneous associations by parental education, family structure, and siblings.

Experiencing parental divorce or separation in childhood is associated with poorer academic achievement, and impairments in physical and mental health. Numerous studies suggest that children and youth who grow up with divorced parents get lower grades and test scores in school and have more symptoms of externalizing and internalizing problems compared to those raised in two-parent nondivorced families. Moreover, these problems are not confined to childhood but tend to persist into adulthood as well. The overall aim of the current thesis was to expand the knowledge of how parental divorce relates to adolescents’ academic achievement, mental health and health complaints, by examining heterogeneity in the outcomes of divorce by parental educational qualifications, family structure, and sibship-type (i.e., biological, half – and stepsiblings). To reach these aims, we utilized data from the large population- based youth@hordaland study of adolescents aged 16–19, that was merged with data from national registries. In Paper I, the aim was to investigate whether the association between parental divorce and adolescents’ grade point average (GPA) was related to parental educational qualifications. Overall, it was found that adolescents with divorced parents had a GPA that was 0.3 standard deviation units lower than adolescents with nondivorced parents. However, while a divorce was hardly related to GPA among adolescents with uneducated parents, divorce was linked to a lower GPA among adolescents with educated mothers, independent of paternal educational qualifications and household income measures. In Paper II, the aim was to investigate the distribution of mental health problems across six different family structures following the steep increase in parents choosing joint physical custody in Norway. It was found that adolescents living in joint physical custody (JPC) displayed significantly lower levels of both externalizing and internalizing problems than their peers living in single parent and stepparent families. Moreover, levels of mental health problems among adolescents in JPC were quite similar to and not statistically significantly different from those living in a two-parent nuclear family. In Paper III, the aims were to investigate how family structures were related to health complaints among adolescents, while capturing the complexity of the modern family by including information about sibship-type (i.e., biological, half- and stepsiblings) in the household. Corroborating the findings from Paper II, it was found that adolescents in JPC reported lower levels of health complaints than their peers in other post- divorce family structures. Moreover, independent of family structure, sharing a household with biological siblings was associated with lower levels of health complaints, while living with stepsiblings was associated with higher levels, but only among girls. Overall, the findings from this thesis suggest that adolescents with divorced parents get lower grades and report higher levels of mental health problems and health complaints than their peers in nuclear two-parent families. Furthermore, parental educational qualifications, adolescents’ post-divorce family structure, and the presence of biological and stepsiblings in the household, may influence the associations between parental divorce and adolescents’ post-divorce adjustment