Investigating Why and How Young Adults Use Protective Behavioral Strategies for Alcohol and Marijuana Use: Protocol for Developing a Randomized Controlled Trial

BACKGROUND: Young adulthood is associated with increased alcohol and marijuana use compared with other developmental periods. Alcohol and marijuana use place individuals at high risk for acute and long-term negative consequences. Despite the relatively large cross-sectional and longitudinal literature on protective behavioral strategies (PBS; behaviors that individuals can use to limit consequences and reduce substance use), little is known about why young adults choose to use PBS on specific occasions or why they might use PBS differently across occasions (ie, quality and consistency). There is significant room for improvement in the conceptualization, application, and understanding of PBS. OBJECTIVE: This study aims to develop a novel, brief web-based and SMS text messaging intervention, with input from young adults who use alcohol and marijuana, which addresses the extent to which motivations for PBS use and nonuse (marijuana or alcohol) and the quality of PBS use (the degree of effectiveness or degree of implementation) differ when using alcohol alone versus concurrently or simultaneously with marijuana. METHODS: This research will be conducted in 2 phases. Phase 1 will involve web-based focus groups (N=100) and cognitive interviews (N=10) to determine why young adults (aged 18-24 years) use or do not use specific PBS related to alcohol and marijuana use and elicit feedback on how motivations and the quality of PBS could be incorporated into a web-based and SMS text messaging PBS intervention as well as elicit feedback on developed intervention material. In phase 2, young adults (N=200; aged 18-24 years), who typically use alcohol and marijuana for at least 2 days per week, will be randomized to either the intervention or waitlist control group. The intervention will be brief, web-based, focusing on self-selected alcohol and marijuana PBS messages and motives for using alcohol- and marijuana-related PBS, and including intervention content delivered via SMS text messages 3 days a week (random day, Friday, and Saturday) over 8 consecutive weeks. All participants will report on PBS use, motivations for PBS use (and nonuse), quality of PBS use, and alcohol and marijuana use in morning surveys timed to occur the day after the intervention SMS text messages for those in the intervention group. RESULTS: Recruitment and enrollment for phase 1 began in January 2022. Recruitment for phase 2 is anticipated to begin in January 2023. Upon completion of the phase 2 pilot, we will examine the feasibility, acceptability, and preliminary effect sizes of the newly developed brief web-based and SMS text messaging intervention. CONCLUSIONS: This study will provide an in-depth understanding of young adults’ PBS use and has the potential to develop a more efficacious intervention for co-occurring or simultaneous alcohol and marijuana behaviors. TRIAL REGISTRATION: ClinicalTrials.gov NCT04978129; https://clinicaltrials.gov/ct2/show/NCT04978129 INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/37106