Developmental trajectories of depressive symptoms from early childhood to late adolescence

Background: Limited information is available on gender differences and young-adult poor outcome in children and adolescents following distinct developmental trajectories of depressive symptoms. Methods: Parent information on depressive symptoms of 4- to 18-year-olds from an ongoing Dutch community-based longitudinal multiple-cohort study (N ¼ 2,076) was used to estimate trajectories from semi-parametric mixture models. The identified trajectories were used to predict depressive problems, general mental health problems, referral to mental health care, and educational attainment in young adulthood. Results: In both genders six distinct developmental trajectories were identified. Gender differencesexistednotonlyinlevel,butalsoinshapeandtimingofonsetofdepressiveproblems.Onlyingirls wasachronictrajectoryofearlychildhood-onsetdepressionidentified.Inbothboysandgirlsagroupwith increasing levels of depressive symptoms was identified that reached a high level around adolescence, although boys showed an earlier onset. Two decreasing trajectories were found in boys, one reaching normative levels of depressive symptoms around late childhood and one around mid-adolescence, while none was found for girls. Individuals who followed elevated trajectories during their whole childhood or starting at adolescence had significantly more depressive and other mental health problems in young adulthood compared to those who followed normative trajectories. Boys in these elevated trajectories showed lower educational attainment, while girls were more likely to have been referred to mental health care. Conclusions: This study shows the value of estimating growth-mixture models separately for boys and girls. Girls with early childhood or adolescence-onset depressive problems and boys with depressive problems during childhood or starting in adolescence are especially at risk for poor outcome as young adults and should be considered candidates for intervention. Keywords: Depressive symptoms, growth mixture model, developmental trajectories, depression, child development, sex differences, longitudinal studies, Child Behavioral Checklist (CBCL), adolescence, adult outcome. Abbreviation: BIC: Baysian Information Criterion. Many studies on depression in childhood and adolescence use a static approach to identify a priori defined distinctive subtypes. Groups are, for example, based on DSM-IV diagnostic criteria (APA, 1994). General conclusions based on such studies are that about one-third of the children and adolescents with elevated levels of depressive symptoms continue to show similar levels of problems later in life. These studies also showed that during adolescence, girls start having more depressive problems than boys (Angold, Erkanli, Silberg, Eaves, & Costello, 2002; Fleming & Offord, 1990; Hankin et al., 1998; Twenge & Nolen-Hoeksema, 2002; Wade, Cairney, & Pevalin, 2002). Other studies use dimensional depressive symptom scores. A metaanalysis of 310 samples of 8- to 16-year-olds revealed that females’ depression scores start to increase from age 12 on, while males’ scores remain stable after age 13 (Twenge & Nolen-Hoeksema