Sexual Minority Status and Marijuana Initiation during Adulthood: A Longitudinal Study Using Nationally Representative Data

Introduction: Sexual minorities (i.e. individuals who identify as lesbian, gay, and bisexual) are at increased risk for marijuana use. However, little is known about initiation during adulthood. This study examines: (1) sexual minority status as a risk factor for marijuana initiation, and (2) the modifying effect of sex (labeled at birth) on this relationship. Methods: We analyzed Wave 1 (2013–2014) and Wave 2 (2014–2015) of the Population Assessment of Tobacco and Health, a nationally representative survey. Participants were n = 10,756 adult never marijuana users. A multivariable logistic regression examined the relationship between sexual minority status and initiation of marijuana use at Wave 2. Multivariable logistic regressions, stratified by sex, were used to assess for effect modification. Covariates were sex, age, race/ethnicity, income, currently attending college, and mental health well-being. Results: Approximately 1.1% of adults initiated marijuana use from Wave 1 to Wave 2. Sexual minority status was associated with 1.57 (95% CI: 1.00–2.46) greater odds of marijuana initiation. In stratified analyses, sexual minority status was associated with greater odds of marijuana initiation for females (Adj OR: 1.97; 95% CI: 1.19–3.26) but not males (Adj OR: 0.84: 95% CI: 0.33–2.16). Conclusions: Sexual minority status is a risk factor for marijuana initiation during adulthood. This relationship was only consistent for females, suggesting that sex may be an effect modifier. However, research designed and powered to directly detect this effect is needed. Findings highlight a need for public health interventions that reduce disparities in marijuana use among sexual minorities.