Developmental Trajectories of Comorbid Alcohol and Tobacco Use Among Young Adults

Background: There is a high co-occurrence of alcohol use with tobacco use and therefore, it is important to identify trajectories of comorbidity to understand these behaviors. Furthermore, the risk factors that produce comorbid behaviors may differ from those that produce a single behavior.

Methods:  Data were derived from a multi-wave study of adolescents, the Minnesota Adolescent Community Cohort study, a population-based, observational cohort study. We fit trajectories to alcohol and tobacco use from ages 18 to 27, and then did analyses to explicitly identify trajectories of concurrent drinking and smoking.  

Results: We identified five trajectories of heavy drinking, including light or non-drinkers (69.4%), late onset moderately heavy drinkers (13.6%), late onset very heavy drinkers (4.2%), developmentally limited heavy drinkers (9.2%), and chronic heavy drinkers (3.6%), and four trajectories of smoking , including non or light smokers (47.1%), moderate smokers (24.4%), late onset heavy smokers (4.9%), and chronic heavy smokers (23.6%). Although the majority of participants in comorbid trajectories were light or non-drinkers, nearly half were either moderate-to- high drinkers or smokers, or some combination thereof.  Detailed results will be reported, including risk factors associated with comorbidity.

Conclusion: Overall, results support positive comorbidity between alcohol and tobacco trajectories through young adulthood. Additionally, identification of common drinking and smoking clusters might provide information for targeted prevention or treatment initiatives.