Abstract
OBJECTIVES: To determine if the association between posttraumatic stress disorder (PTSD) and substance use (alcohol misuse or smoking tobacco) is mediated/moderated by exercise or volunteering among aging (≥40 years) men who have sex with men (MSM), and if this mediation/moderation differs by HIV serostatus. METHODS: Multicenter AIDS Cohort Study data were used. Three datasets with PTSD measured during different time periods (10/1/2017-3/31/2018, 898 men; 4/1/2018-9/30/2018, 890 men; 10/1/2018-3/31/2019, 895 men) were analyzed. Longitudinal mediation analyses estimated the mediation effect of exercise and volunteering on the outcomes. RESULTS: Nine percent of MSM had evidence of PTSD. There was no statistically significant mediation effect of exercise or volunteering regardless of substance use outcome. The odds of smoking at a future visit among MSM with PTSD were approximately double those of MSM without PTSD. Results did not differ by HIV serostatus. DISCUSSION: There is a particular need for effective smoking cessation interventions for aging MSM with PTSD.