Relations between Positive Temperament, Substance Use, and Internalizing Problems among Adolescents and Young Adults with and without Medical Conditions

Background: Substance use problems are prevalent during emerging adulthood and may be particularly harmful for individuals with medical conditions. Understanding the role of positive temperament in substance use for adolescents and young adults (AYAs) may facilitate the identification of intervention and prevention targets given the complex relations between positive emotions and substance use. Objective: To examine whether components of positive temperament differentially relate to substance use in a sample of AYAs with and without medical conditions. Internalizing problems were examined as a secondary outcome given their comorbidity with substance use. Method: In a cross-sectional study that took place in 2015–2016, 494 AYAs (M_age = 19.30 years, SD = 1.33, 73% female) who were enrolled in college completed online questionnaires in a laboratory regarding their levels of positive temperament (i.e., high intensity pleasure and positive affect) as well as their substance use and internalizing problems. The primary analyses were conducted using structural equation modeling. Results: For healthy AYAs, high intensity pleasure was positively associated with drug and alcohol use problems and positive affect was negatively associated with drug use problems. Among AYAs with medical conditions, high intensity pleasure was positively associated with alcohol use problems. Positive affect was negatively associated with internalizing problems for both groups. Conclusions/Importance: Findings identify paths between components of temperament and substance use and internalizing problems that may inform prevention and intervention efforts tailored to the unique and overlapping needs of AYAs with a range of healthcare demands.