Homosexuality and bisexuality have been associated to increased risks of substance use. Affiliation with the gay culture is one of the explanatory models. According to this model, homosexual persons should, compared to heterosexual persons, preferentially use (or at least try) substances which are usual within the gay scene.

To explore the choice of lifetime substance use among heterosexual, bisexual and homosexual men.

The C-SURF study concerns young Swiss male adults who have to go through the mandatory recruitment process at the Swiss army. Data were collected between August 2010 and November 2011. The questionnaire was about the participants’ socioprofessional and family background, their consumption of alcohol, cannabis and other drugs, as well as their personality. The final sample included 5990 males between 17.9 and 31.4 years old (mean=20.01, sd=1.24).

5371 (89.7%) of subjects declared being exclusively attracted by females, 442 (7.4%) by males and females and 62 (1.0%) by males only. A multinominal logistic regression revealed an increased risk of homosexual men to have ever used poppers (OR 1.57), party drugs (Ecstasy, GHB etc.) (OR 2.18) and cannabis (OR 1.34). Homosexual men had an increased risk of lifetime use of poppers (OR 7.29), and cocaine (OR 4.47), and a reduced risk of alcohol use (OR 0.45).

The choice of drugs seems to be influenced partly by sexual affinities. In addition to the affiliation with the gay culture (especially poppers), the minory stress model may help to explain cannabis use among bisexual subjects