Applying Construal Level Theory to Develop and Test an Interactive Text Messaging Adjunct Intervention to Reduce Heavy Drinking and HIV Risk - Project Summary/Abstract Heavy drinking is common among young adult men who have sex with men (MSM), which increases likelihood of engaging in sexual behaviors with risk for HIV. Text messaging - a ubiquitous technology- is starting to be used to address alcohol/HIV risk, but more theory-based work is needed to rigorously develop and test the content of text messages to optimize behavior change. Thus, in this MOSAIC K99/R00, the applicant will, in the K99 phase, develop and refine, and then, in the R00 phase, test the efficacy of an interactive text messaging program to reduce heavy drinking and HIV risk utilizing construal level theory (CL T) to define intervention targets. Both prior evidence and theory inform this proposal. Specifically, CL T suggests that individuals can think about a behavior or behavior change (e.g., drinking less) abstractly (e.g., why the person wants to drink less) or concretely (e.g., how the person will limit their drinking). Interventions and experimental manipulations based on CL T use the why/how paradigm to ask participants a series of why/how questions intended to induce abstract or concrete thinking, respectively. Evidence suggests that abstract thinking may enhance motivation to change whereas concrete thinking may facilitate effective implementation of behavior change; however, CL T has largely been applied to facilitate weight loss and reduced smoking. Despite its applicability and potential, CL T has yet to be applied to alcohol and HIV research. In this proposal, the applicant seeks to develop and test CL T-based why/how text messages to induce abstract/concrete thinking, respectively, about alcohol and HIV risk and in turn reduce alcohol use, risky sexual behaviors, and negative consequences of drinking, at the day-level. During the K99 phase, the applicant, working with an advisory panel of young adult heavy drinking MSM, will develop and refine the text messaging protocol (Aim 1; months 1-9). We will then conduct a series of pilot tests and exit interviews (2 rounds of n=12 participants) to iteratively assess and improve feasibility and acceptability of the intervention (Aim 2; months 10-24). During the R00 phase, participants (N=240) will first complete baseline assessment and GamePlan - an existing brief alcohol/HIV intervention to enhance motivation to change with demonstrated promise. Participants will then be micro-randomized at the day-level (i.e., randomized every day) for 8 weeks to receive (1) CLT-concrete messages; (2) CLT-abstract messages; (3) control messages; or (4) no messages. Participants will complete assessments daily and at the end of the intervention. These aims are in line with the applicant's goals to acquire training in (1) developing and testing behavioral interventions (Dr. Christopher Kahler); (2) conducting micro-randomized trials (Dr. Stephanie Goldstein), and (3) analyzing intensive longitudinal data (Dr. Jennifer Merrill}, and to facilitate a successful transition to independence. This project will enable the applicant to work with a highly skilled, experienced team, and provide data for a future R01 to test the effectiveness of the intervention on a larger scale, as well as provide critical theoretical information regarding potentially novel mechanisms of behavior change in alcohol/HIV research.