RESUMEN
OBJECTIVES: This paper investigates the trajectories of depression symptoms in adolescents and young adults, and explores factors associated with their depression. METHOD: For each respondent, three waves of data were collected in 2006, 2009 and 2013 from adolescents and young adults aged 10 to 24 years. The modified Center for Epidemiological Studies Depression Scale was used to interview participants, while the generalised estimating equation (GEE) model was used to identify whether certain factors were associated with depression. RESULTS: The mean depression scores in 2006, 2009 and 2013 were 29.76, 30.80 and 30.51 respectively. Compared to boys, girls reported higher initial levels of depressive symptoms. The depression score was found to be highest among adolescents aged 15 to 17 years. Depression among young people was associated with age, gender, marital status, education levels, general health and living location. CONCLUSION: Using longitudinal design, this research demonstrated the different trajectories of depression scores between boys and girls over time and provided evidence for interventions improving adolescent mental health in a semi-urban area of Vietnam.