Acute Alcohol Consumption Directly Increases HIV Transmission Risk: A Randomized Controlled Experiment.

BACKGROUND: Alcohol consumption has frequently been purported as a driver of condomless sex and HIV transmission, but to date, experimental evidence for the causal risk-taking impact of alcohol among HIV-positive populations is lacking. The present experiment sought to determine whether acute alcohol consumption has a direct causal impact on condomless sex intentions among HIV-positive men-who-have-sex-with-men (MSM), and to assess whether alcohol's impact differs between MSM who are HIV-positive versus HIV-negative.

METHODS: In a randomized controlled alcohol administration experiment, HIV-positive and HIV-negative MSM were brought into a specialized barroom laboratory and randomly assigned to beverage consumption condition: alcohol (target blood alcohol concentration = 0.080%), placebo alcohol (target blood alcohol concentration = 0.000%), or water (control). Participants then underwent a video-based sexual arousal manipulation (sexually aroused/nonaroused) and indicated their intentions to engage in condom-protected and condomless sexual acts in a standardized paradigm. The primary outcome entailed intentions to engage in condomless receptive and condomless insertive anal sex.

RESULTS: A total of 282 MSM (141 HIV-positive; 141 HIV-negative) completed experimental procedures. MSM who received alcohol reported significantly stronger intentions to engage in condomless sex than those who received placebo alcohol or water (F(1,274) = 9.43, P = 0.002). The impact of alcohol did not differ between HIV-positive and HIV-negative MSM (F(1,274) = 1.86, P = 0.174).

CONCLUSIONS: The present investigation entailed the first risk-focused alcohol administration experiment to involve an HIV-positive sample, and results demonstrated that consuming alcohol had an independent, causal impact on intentions to engage in sexual behaviors that can result in HIV transmission. Findings strongly suggest that alcohol-focused initiatives should be incorporated into HIV prevention efforts.