Effects of syndemic psychiatric diagnoses on health indicators in men who have sex with men

Objective: Syndemic theory posits that co-occurring problems (e.g., substance use, depression, and trauma) synergistically increase HIV risk in men who have sex with men (MSM). However, most investigations have assessed these problems additively using self-report. Method: In a sample of HIV-negative MSM with trauma histories (n = 290), we test bivariate relationships between four clinical diagnoses (substance use disorder [SUD]); major depressive disorder [MDD], posttraumatic stress disorder [PTSD], and anxiety disorders) and their additive and interactive effects on three health indicators (i.e., high-risk sex, visiting the emergency room [ER], and sexually transmitted infections [STIs]). Results: We found significant bivariate relationships between SUD and MDD (ξ² = 4.85, p = .028) and between PTSD and MDD (ξ² = 35.38, p = .028, p = .001) but did not find a significant relationship between SUD and PTSD (ξ² = 3.64, p = .056). Number of diagnoses were associated with episodes of high-risk sex (incidence rate ratio [IRR] = 1.14, 95% CI [1.03, 1.26], p = .009) and visiting the ER (odds ratio = 1.27; 95% CI [1.01, 1.60], p = .040) but not with STIs. No interactions were found between diagnoses and health-related indicators. Conclusions: This is the first study to demonstrate additive effects of clinical diagnoses on risk behavior and health care utilization among MSM with developmental trauma histories. Results indicate the need to prioritize empirically supported treatments for SUD and MDD, in addition to trauma treatment, for this population.