The majority of young adults who use both alcohol and marijuana do so simultaneously. Simultaneous Alcohol and Marijuana (SAM) use is defined as using alcohol and marijuana at the same time so that their effects overlap. Individuals who engage in Concurrent Alcohol and Marijuana (CAM) use are often characterized as those who report both alcohol and marijuana use within the same time period (e.g., past month, past week). An increasing body of literature has documented CAM and SAM use on a given day among young adults. Event-level findings show SAM use is associated with increased risk for consequences, compared to marijuana use alone or CAM use. Given that the investigators' focus in this application is on daily-level substance use behaviors, the investigators define CAM use as using both substances on the same day, but not so that their effects overlap. Interventions should focus on reducing drinking as well as drinking that occurs in conjunction with marijuana use to provide a more comprehensive evaluation of intervention efficacy. The proposed research in this application will develop and test a novel online and text message (TM) protective behavioral strategies (PBS) intervention to reduce alcohol, marijuana, CAM, and SAM use and related negative consequences among young adults.

One way interventions could prevent or reduce alcohol- and marijuana-related consequences is by promoting the use of PBS, which are behaviors that individuals can use to limit consequences and/or reduce substance use. PBS are often incorporated into brief interventions or TM interventions in the form of skills training. Despite the empirical support for including PBS content in brief interventions, findings have been inconclusive regarding whether PBS mediate intervention efficacy among college students. One possible explanation is that skills-based PBS interventions prematurely focus on "how" to use PBS, but not "why" PBS might be used or used with high quality. Research is needed to determine motivations for when and why young adults may or may not decide to use PBS to reduce harm while using alcohol and/or marijuana, which can then enable investigators to better address these motivations in brief interventions. Research has yet to examine how alcohol and marijuana PBS use on a given day relates to an individual's use of alcohol alone or marijuana alone in comparison to CAM or SAM use. The proposed study will fill these critical gaps by identifying the extent to which motivations for PBS use and nonuse (marijuana or alcohol) and quality of PBS use (degree of effectiveness or degree of implementation) differ when using alcohol alone versus concurrently or simultaneously with marijuana. The overall goal of this research is to inform a pilot study of a newly developed alcohol and marijuana PBS intervention. The proposed research will (1) collect pilot data to establish feasibility and acceptability and test the interactive online and TM PBS intervention (baseline, 2-month) while also (2) collecting event-level data to examine daily-level associations among PBS motivation/quality, PBS use and non-use, alcohol and/or marijuana use, and negative consequences with a focus on how PBS may differ on CAM or SAM use days compared to alcohol-only days.

Aim 1: Examine motivations for alcohol and marijuana PBS use (and non-use of PBS) as well as quality of PBS use among young adults (ages 18-24) who use both alcohol and marijuana. The present study will conduct online focus groups (10 groups, N=10 individuals per group) and cognitive interviews (N=10) to determine why young adults use or do not use specific PBS related to alcohol and/or marijuana use. Focus groups will address how PBS use or motivations to avoid consequences may differ by gender (male, female, non-binary). Focus groups and cognitive interviews will discuss the level of quality in which PBS are used and various contexts in which PBS may or may not be used. Discussions will consider use of either substance alone on a given day as well as SAM or CAM use on a given day and will include ways in which the motivations and quality of PBS could be incorporated into an online and TM PBS intervention, as well as elicit feedback on mock intervention material. Using an exploratory sequential mixed methods design, an iterative process of focus groups and cognitive interviews will inform the development and delivery of the intervention to be tested in the pilot study (Aim 2). Aim 1 is not a clinical trial.

Aim 2: Conduct a pilot study with young adults (N=200; ages 18-24), who typically use alcohol and marijuana at least two days per week, to determine feasibility, acceptability, and preliminary effect sizes (to inform a future R01 application). Participants will be randomized to either the intervention or wait-list control. The intervention is a brief interactive online intervention focusing on self-selected alcohol and marijuana PBS messages and motives for using alcohol- and marijuana-related PBS and includes intervention content delivered via TMs three days a week (random day, Friday, Saturday) over eight consecutive weekends. All participants will report PBS use, motivations for PBS use (and non-use), quality of PBS use, readiness to change, and alcohol and marijuana use in morning surveys timed to occur the day after the intervention TMs for those in the intervention group. The proposed research in this application will provide an in-depth understanding of young adults' PBS use and has potential to develop a more efficacious intervention for these co-occurring or simultaneous alcohol and marijuana behaviors. Aim 2 is the clinical trial.