Simultaneous Alcohol and Cannabis Use with a Romantic Partner Present: Daily Associations with Drinking, Intoxication, and Consequences among Young Adults

Simultaneous alcohol and cannabis use (commonly referred to as SAM) represents a significant public health concern for young adults. Romantic partners are a strong source of influence on substance use; however, research on SAM use among young adults with romantic partners is sparse. Using daily data, we tested whether SAM use was more likely on alcohol use days with a romantic partner present (versus without), and whether SAM use days (versus alcohol-only use) with a romantic partner present were differentially associated with alcohol use outcomes and sexual behaviors. A community sample of 308 young adults (ages 18-25) who reported at least one day of alcohol use with a romantic partner present completed six 14-day bursts of twice-daily surveys across two years. Participants completed daily measures on alcohol and SAM use, partner presence during use, subjective intoxication, positive and negative alcohol-related consequences, and sexual behaviors. On alcohol use days with a partner present (versus without), individuals were significantly more likely to report SAM use. On SAM use (versus alcohol-only) days with a partner present, individuals reported consuming more drinks, greater subjective intoxication, more alcohol-related positive consequences, and a greater likelihood of sex while intoxicated. Reporting a greater proportion of SAM use days (versus alcohol-only days) with a partner present across the entire study was significantly associated with overall greater subjective intoxication and a greater likelihood of having sex while intoxicated. The presence of a romantic partner may increase the risk of engaging in SAM use at the daily level, and SAM use with a partner present is associated with high-risk drinking behaviors and more positive alcohol-related consequences compared to alcohol-only use.