Trajectories of Depressive Symptoms in Canadian Emerging Adults

Objectives. We identified courses of depressive symptoms in an epidemiological sample of emerging adults. Methods. We used latent class growth modeling to identify trajectories of depressive symptoms measured by the 12-item Center for Epidemiological Studies Depression Scale (CES-D) during a 14-year follow-up of 2825 Canadian youths aged 10 to 25 years enrolled in the National Longitudinal Survey of Children and Youth between 1994 and 2009. Results. After adjustment for youth, parent, and family factors, the 3 distinct trajectories of depressive symptoms were minimal (55%; CES-D < 6), subclinical (39%; CES-D = 9-13), and clinical (6%; CES-D > 18). All trajectories exhibited a parallel course, with peak symptoms at 15 to 17 years of age. Subclinical and clinical symptoms were more common than minimal symptoms in female youths and in respondents with lower self-concept, lower socioeconomic status, poorer interpersonal relations, and chronic health conditions (P < .01). Conclusions. Among emerging adults, trajectories of depressive symptoms do not trend upward or downward, and variables associated with identified trajectories demonstrated dose-response effects that agreed with vulnerability-stress theories of depression.