Changes in substance use during the COVID-19 pandemic: Longitudinal analysis of risk behavior and mental health of MSM using HIV pre-exposure prophylaxis

Background: Changes in substance use behavior, as well as mental and sexual health among men having sex with men (MSM) due to the COVID-19 pandemic remain unclear.

Methods: Design: Longitudinal analysis of a large, ongoing, multicenter, pre-exposure prophylaxis (PrEP) cohort (NCT03893188) in Switzerland. Participants: HIV-negative MSM aged ≥18 with at least one questionnaire before and one after the SARS-CoV-2 pandemic start.

Outcomes: (1) Self-reported substance use (including cannabis, cocaine, Ecstasy, and Chemsex- related substances), (2) mental health, defined as anxiety and depression scores assessed by the Patient Health Questionnaire-4 and (3) sexual behavior, including the number of sexual partners and sexual happiness. Outcomes were assessed over 7 periods of time over 1-year, corresponding to different COVID-19 prevention measures in Switzerland. We performed pairwise comparisons between periods (Wilcoxon Signed Rank test).

Results: Data from 1043 participants were included. Substance use did not vary markedly over time, except for the use of Ecstasy (i.e., decline over time after pre-lockdown compared to baseline, p<.001) and the use of Chemsex-related substances (i.e., decline during first lockdown and easing, p=.002). Depression scores worsened in the 2nd wave and 2nd lockdown period compared to pre-pandemic scores. Whilst sexual happiness remained stable over time, sexual behavior followed a biphasic pattern over time, with a first decrease during the first lockdown and easing, and a second decline during the second wave and lockdown.

Conclusion: In this longitudinal analysis of a large PrEP cohort enrolling MSM, changes in substance use and sexual behavior were observed (e.g., decline in Chemsex-related substance and Ecstasy use, downward trend in the number of sexual partners and the occurrence of sex with casual partners), as well as a worsening of depression scores over the different phases of the COVID-19 pandemic.