Population-level patterns and mental health and substance use correlates of alcohol, marijuana, and tobacco use and co-use in US young adults and adults: Results from the population assessment for tobacco and health

Background and Objectives: This study identified the most common patterns of current alcohol and marijuana use with the spectrum of tobacco products (cigarettes, hookah, e-cigarettes, cigars/little cigars, and other products), among US young adults and older adults and examined associations of mental health and substance use problems with each pattern. Methods: Wave 1 adult dataset (2013–2014) of the Population Assessment of Tobacco and Health (PATH) Study. Weighted analyses estimated the prevalence of the top 10 patterns of current alcohol, marijuana, and tobacco use and co-use separately by young adults aged 18–24 (n = 9,112) and adults 25+ years (n = 23,208). Multivariable models examined associations of substance use and mental health problems to patterns of use, adjusting for demographics. Results: Across both age groups, alcohol-only use was the most popular use pattern (20.7% for young adults and 32.2% older adults) however poly-substance use patterns were more frequent than single use patterns. Cigarettes were the only tobacco product used exclusively; all other tobacco products were used with together, or with alcohol or marijuana. Only one young adult pattern emerged containing e-cigarettes, and this pattern included co-use with alcohol and cigarettes (1.3%). Mental health and substance use problems were most strongly correlated with dual and poly-substance use patterns, regardless of age. Scientific Significance: Prevention and intervention campaigns should focus on multiple product use, as single substance use is uncommon. Alcohol is common in all patterns, suggesting it should also gain more focus in marijuana and tobacco prevention and intervention programs. (Am J Addict 2018;27:491–500).