BACKGROUND: Chemsex, characterized by the intentional use of specific drugs to enhance sexual experiences during group sessions, represents a challenge for the health of some sexually active communities, such as men who have sex with men (MSM). MSM may experience mental health issues associated with chemsex participation. This survey aims to investigate the characteristics, prevalence, and correlates of sexualized drug use (SDU) and chemsex with a focus on the emotional vulnerability associated with chemsex and SDU engagement among MSM at high risk of sexually transmitted infections (STI). METHODS: A self-administered anonymous questionnaire to investigate demographical data, attitudes toward substance dependence, sexual behaviors and vulnerability for common mental disorders (CMD), was offered to consecutive MSM attending the STI/HIV Unit of San Gallicano Dermatological Institute of Rome, Italy, from 1 to 30 November 2023. The Mann-Whitney and Fisher's test were used to assess differences in terms of sexual behavior, SDU, STI risk and vulnerability for CMD between MSM who don't engage in SDU, who engage only in SDU (no chemsex) and chemsex. RESULTS: One hundred and twenty-two MSM agreed to participate. Overall, 47.3% (57/119) were people living with HIV (PLWH) on antiretroviral therapy (ART)
fifty (40.9%, 95% CI: 32.7-49.9) participants reported SDU, 24 (19.7%, 95% CI: 13.6-27.6) of which reported chemsex. Participants reporting SDU or chemsex were in unstable relationships (p = <
0.01), engaged in group sex (p = <
0.01) and had more than 10 sexual partners in the previous year (p = <
0.01) compared to those who denied SDU. Chemsex participants were more likely to use condoms inconsistently (p = 0.02), have a history of STIs (p = 0.02), and have had over 10 sexual partners in the past year (p = 0.04) than those who only engaged in SDU. Chemsex participants used specific and exclusive drugs when compared to other MSM engaged in SDU. Overall, 35 (28.7%
95% CI: 21.4-37.2) and 52 (42.6%
95% CI: 34.2-51.5) participants showed symptoms of depression and anxiety, respectively. Chemsex involvement showed a strong association with symptoms of depression compared with no-SDU andno- chemsex (COR = 3.8
95% CI: 1.22-11.6
p <
0.01), particularly among PLWH (p = 0.04). CONCLUSIONS: Depression may be associated with chemsex behavior, particularly in MSM with HIV. SDU, in particular chemsex, are proxies in practitioners for increased STIs risk and severe psychological distress, both as determinants and outcomes. Healthcare professionals in STI centers need more awareness of SDU and ongoing evaluation with a larger population.