Long-term development of mood states and substance use in a Swiss cohort of youths at risk

Background: Substance use and mental health disorders are strongly associated. The rates of co-morbidity vary according to the population and methodology used. However, it can be reasonably stated that co-morbidity is common and significant. Mental disorders, including depressive mood, anxiety and conduct disorders, are the most often mentioned predictors for substance use. Aims: The main topic of interest is the interrelationship between mood and substance used over time in a cohort of adolescents and young adults. Method: To explore the courses of mood and substance use in a cohort of 614 adolescents and young adults (aged 12–20) using grouping analysis. To determine empirical patterns of mood over time a cluster analysis (k-means) was performed. Four groups differing in their mood states over time (stable low; stable high; increaser; decreaser) were obtained. Conclusions: There is an important relationship between mood states and substance use. Adolescents with mood disorder constantly use more drugs t...