Trends in adolescent mental health problems 2004-2020: do sex and socioeconomic status play any role?

Aims: This study aims to investigate trends in four types of adolescent mental health problems; that is, psychosomatic symptoms, depressive symptoms, suicidal ideations, and suicide attempts 2004-2020. A second aim is to investigate the moderating roles of socioeconomic status and sex in these trends. Methods: The analysis is based on repeated cross-sectional data 2004-2020 among grade 9 students in secondary schools in a Swedish county. In total, data from 19,873 students were included in the analysis. We fitted linear and logistic regression equations and used survey-years' coefficients to estimate the trends. We also estimated the moderating effects of socioeconomic status and sex using interactions between survey year and socioeconomic status and sex, respectively. Results: The trends in all mental health problems declined over time. Through its interaction with survey year, socioeconomic status moderated the trends; psychosomatic symptoms (B = -0.115, P<0.001), depressive symptoms (B = -0.084, P<0.001) and suicidal ideations (odds ratio 0.953, confidence interval 0.924-0.983) significantly declined over time among those with high socioeconomic status. However, socioeconomic status did not have an association with the trend in suicide attempts. Interaction between sex and year of survey was associated with significant decreasing trends in depressive symptoms and suicidal ideations only among girls. Conclusions: Adolescent mental health problems have decreased over time, but only for adolescents with high socioeconomic status, or only in depressive symptoms and suicidal ideations for girls. The results shed light on the growing inequalities in health outcomes across levels of socioeconomic status.