Objective: Our principal objective was to determine whether psychosocial stress raises the risk of HIV infection among gay and bisexual men. If so, we also aimed to evaluate the evidence for the underlying mechanism, specifically whether stress has an intermediate effect on sexual risk behaviour or an independent, cofactor effect.
Methods: Participants were recruited through the provincial HIV diagnostic laboratory, physicians and community organizations in Ontario, Canada, 1998-2006. Confirmed recent seroconverters (n = 123 cases) were asked about stressful life events and behaviour during the likely period of infection (median 8, range 3-33 months). HIV-negative controls (n = 240) were asked about an equivalent time period. We used logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs).
Results: Cases reported more stressful life events (median = 3, 33% 5 or more) than controls (median = 2, 20% 5 or more). Compared to men who reported no events, risk of HIV infection increased with the number of events, to a 2.5-fold increase in risk among men reporting 5 or more (95% CI 1.3, 4.7). The association weakened when adjusted for sexual risk behaviour (OR = 1.7, 95% CI 0.82, 3.6) and when restricted to men who engaged in unprotected receptive anal sex with an HIV-positive or status unknown partner (OR = 1.3, 95% CI 0.50, 3.6).
Conclusions: Gay and bisexual men experiencing stressful life events were at increased risk of HIV infection. This effect was mediated by sexual risk behaviour. We recommend that coping strategies in response to stress be considered in prevention research and health policy.