Psychosocial Problems Syndemically Increase Adolescent Substance Use: Findings From a Cross-sectional Survey of 82,812 Chinese Adolescents.

A growing body of studies have indicated the associations between substance use and psychosocial problems in adolescents. However, few of them have examined whether these psychosocial problems form a syndemic, which means the co-occurrence of psychosocial problems accompanied by additional effects on substance use.We conducted a cross-sectional survey with 82,812 Chinese adolescents who were selected using a multistage random procedure. Bivariate associations were estimated between selected syndemic indicators and adolescent substance use. Multivariate logistic regression was used to estimate the association between the syndemic indicator count score (the count of syndemic indicators) and adolescent substance use. In addition, cluster analysis was used to partition participants reporting at least one of syndemic indicators to assess associations between resolved cluster memberships and adolescent substance use.All selected syndemic indicators were associated with each other and with adolescent substance use. As the number of syndemic indicators increases, stronger associations with substance use were found in our analysis: the range of adjusted OR was from 1.57 (95% CI: 1.38-1.79) for 1 syndemic indicator to 9.45 (95% CI: 7.60-11.76) for 5 or 6 syndemic indicators. There was no effect modification of gender on these additive associations. The multivariate logistic regression indicated that the cluster membership of nonlow SES academic failures has the highest odds of using substance (OR = 2.26, 95% CI: 2.12-2.41), compared to students reporting none syndemic indicators.Our findings support the syndemic hypothesis that adolescents bearing multiple psychosocial problems experience additive risks of using substance. Our findings support that a comprehensive approach to substance use prevention in adolescents would necessitate the involvement of a variety of providers.