(PS6-D82) Examining Within-person Associations Between Alcohol and Marijuana Use and Hooking up Among Adolescents and Young Adults

With simultaneous alcohol and marijuana (SAM; i.e., used so that their effects overlap) use being both highly prevalent and problematic among adolescents and young adults, research is needed to examine how the use of alcohol and marijuana are associated with hooking up. In the present study, hooking up was defined as an event in which an individual was physically intimate (any of the following: kissing, touching, fingering, oral sex, vaginal sex, anal sex) with someone whom they were not dating or not in a romantic relationship with at the time, and in which the participant understood there was no mutual expectation of a romantic commitment. This study aimed to examine whether or not participants would be more likely to hookup (1) on days with alcohol use, (2) on days with marijuana use, (3) on days with higher than their average alcohol use (number of drinks), (4) on days with higher than their average marijuana use (hours high), and (5) on days with SAM use. Participants included 15-25-year-olds (N =937) recruited in Texas, who were part of a longitudinal ecological momentary assessment study on drinking cognitions and alcohol use. The study design consisted of 3-week bursts (8 surveys per week) that were repeated quarterly over the 12-month study period. Participants (61.7% female) were on average 20.1 years old (SD = 3.2) at baseline. Sexual orientation representation of the sample was 64.2% straight, 17.3% bisexual, 5.8% lesbian/gay, 5.5% pansexual, and 7.1% other. Mixed effects logistic regression models were estimated to evaluate the associations between substance use (i.e., alcohol and marijuana) and hooking up. Within-person findings indicated that on days with alcohol use (OR = 1.82, p < 0.0001) and on days with marijuana use (OR = 1.89, p < 0.0001) participants were more likely to hook up, relative to non-use days. In addition, on drinking days with higher alcohol use than their own average, participants were more likely to hookup (OR = 1.08, p = 0.0371). Among marijuana use days, hours high was not associated with hooking up at the within-person level. Finally, SAM use days were not significantly associated with hooking up, relative to days with alcohol or marijuana use but no overlapping effects. Together, findings suggest that daily-level use of alcohol and marijuana are associated with hooking up, but using them simultaneously had no added effect compared to individual use of each substance. Overall results underscore alcohol use on a given day, given that both using any alcohol and drinking more than one’s own average were associated with greater likelihood of hooking up. Additional research is needed to assess daily and longitudinal patterns of alcohol and marijuana use and associated hooking up outcomes (e.g., positive and negative consequences) in this population in order to inform the development of interventions and policies.