7 - (IOP 27) Validation of the Stimulant Use Motives Scale and Assessing Its Relationship to Psychosocial and Sexual Health Variables Among Men Who Have Sex with Men in the U.S

Stimulant use (e.g. cocaine, crystal methamphetamine) among men who have sex with men (MSM) is associated with poor HIV prevention related outcomes, such as suboptimal adherence to daily oral pre-exposure prophylaxis (PrEP). Assessing MSM’s patterns of and motives for using stimulants can help identify factors linked to underlying psychological factors and in, turn, support the development of more effective HIV prevention interventions for this population.

In this study, we validated the Stimulant Use Motives Scale (SUMS), an adaptation of the Drinking Motives Questionnaire-Revised short form (DMQ-R-SF), in a national U.S. sample of 238 adult MSM. We used baseline data from a large RCT for HIV-negative MSM who use stimulants in the context of condomless sex. Using a structural equation modeling framework, we used confirmatory factor analysis to measure four latent variables and assess the predictive validity of the SUMS on stimulant use outcomes. Outcomes included polydrug use; frequency of stimulant use in the context of sex, the number of stimulant use binges and a latent variable encompassing withdrawal symptoms and common life problems (i.e., consequences) associated with stimulant use, all measured with reference to the past four months.

Confirmatory factor analyses indicated that a four-factor model, consistent with the DMQ-R-SF (short form), provided acceptable fit: χ²(46) =84.5, CFI = 0.99, TLI = 0.99, SRMR = 0.07, and RMSEA = 0.06 (95% CI: 0.04–0.08). The four factors identified were social (i.e. making social situations more enjoyable), enhancement (i.e. feeling euphoric), coping (i.e. helping mood), and sexual (i.e. facilitating sexual encounters). A separate structural regression model, adjusted for age, revealed that social motives were significantly negatively associated with stimulant use-related consequences (b = -0.402, p = 0.005). Enhancement motives were significantly positively associated with past frequency of stimulant use in the context of sex (b = 0.483, p = 0.001) and binges (b= 1.385, p = 0.023). Coping motives were positively associated with increased stimulant use-related consequences (b= 0.507, p= 0.002). Sexual motives were significantly negatively associated with polysubstance use (b = -0.196, p = 0.035), positively associated with number of binges (b = 1.664, p = 0.007), and positively associated with stimulant use-related consequences (b = 0.305, p = 0.048). Age, as a covariate, was found to be associated with polysubstance use, binges, and stimulant use-related consequences, with older age linked to worse stimulant use-related outcomes.

Findings suggest that substance use prevention and psychosocial interventions for MSM who use stimulants should focus on addressing unique motivations for using stimulant use in the context of sex. Attention should be given to older MSM, as they have been associated with multiple negative stimulant use-related outcomes. Cognitive-behavioral interventions may benefit from leveraging the perceived protective nature of social motives for stimulant use by incorporating social behavioral activation strategies, while also focusing on challenging perceptions of stimulant effects and exploring alternative coping and sexual health behavior strategies.