Sex-Specific Depressive Symptom Trajectories Among Adolescents in Los Angeles County, 2013 to 2017.

Objective: After remaining stable for many years, the prevalence of depression among adolescents increased over the past decade, particularly among girls. In this study, we used longitudinal data from a cohort of high school students to characterize sex-specific trajectories of depressive symptoms during this period of increasing prevalence and widening gender gap in adolescent depression. Method: Using data from the Health and Happiness Cohort, a longitudinal 8-wave study of high school students residing in Los Angeles County from 2013 to 2017 (N = 3,393), we conducted a multiple-group, latent class growth analysis by sex to differentiate developmental trajectories in depressive symptoms scores measured by the Center for Epidemiological Studies- Depression (CES-D) scale (range, 0-60). Results: A 4-class solution provided the best model fit for both girls and boys. Trajectories among girls included low stable (35.1%), mild stable (42.8%), moderate decreasing (16.2%), and high arching (5.9%). Trajectories among boys included low stable (49.2%), mild increasing (34.7%), moderate decreasing (12.2%), and high increasing (3.9%). Average scores consistently exceeded or crossed the threshold for probable depression (≥16). Across comparable sex-specific trajectory groups, the average CES-D scores of girls were higher than those of boys, whose average scores increased over time. Conclusion: In a diverse cohort of students in Los Angeles County, depressive symptom trajectories were comparable to prior time periods but with a higher proportion of students in trajectories characterized by probable depression. Trajectories differed by sex, suggesting that future research should consider differential severity and onset of depression between boys and girls.