Self-initiated continuation of and adherence to HIV pre-exposure prophylaxis (PrEP) after PrEP demonstration project roll-off in men who have sex with men: associations with risky decision making, impulsivity/disinhibition, and sensation seeking

The objective of this study was to examine differences in the levels of risky decision making and other frontal system behavior constructs in relation to self-initiated continuance of HIV pre-exposure prophylaxis (PrEP) and PrEP adherence outcomes among men who have sex with men (MSM) following completion of a clinical PrEP trial. At the last PrEP trial visit, study provided PrEP was discontinued and participants were navigated to the community for PrEP continuation. In this cross-sectional analysis, 84/187 (45%) MSM who completed a prospective observational post-PrEP trial follow-up visit at the University of California San Diego were included. PrEP adherence was measured using dried blood spot tenofovir diphosphate (TFV-DP) levels. Risky decision making was assessed using the Iowa Gambling Task (IGT) and the Balloon Analogue Risk Task (BART), while impulsivity/disinhibition, sensation seeking, and substance use were assessed via standardized self-report questionnaires. A total of 58/84 (69%) of MSM who completed the 12-month post-study visit continued PrEP. Of those, n = 46 (79%) reached TFV-DP levels associated with adequate adherence. Individuals who elected to continue PrEP 12 months post-trial had riskier decision making on BART, but less impulsivity/disinhibition compared to individuals who did not continue PrEP. Neither risky decision making nor impulsivity/disinhibition/sensation seeking nor substance use correlated with PrEP adherence. Our findings suggest that those with risky decision making may have greater insight into their HIV risks, and therefore be more likely to continue to use PrEP. However, elevated impulsivity/disinhibition, indicative of greater neurobehavioral alterations, was negatively associated with PrEP continuance and is a potential target for future interventions to help people link to PrEP.