Sexual consent and chemsex: a quantitative study on sexualised drug use and non-consensual sex among men who have sex with men in Amsterdam, the Netherlands.

Background: Chemsex (drug use to enhance sex) has emerged among men who have sex with men (MSM). Non-consensual sex (NCS) is hypothesised to occur frequently under the influence of chemsex, however data are scarce. In this cross-sectional study, it was aimed to assess whether NCS is associated with chemsex.

Methods: We offered a survey about chemsex in the past 6 months (crystal methamphetamine, mephedrone and/or gamma-hydroxybutyrate/gamma-butyrolacton use) and NCS (sexual experiences beyond one's limits or unpleasant sexual experiences) in the past 5 years to Amsterdam-located gay dating platform users. Associations were assessed using χ² test, Fisher's exact test and multivariable logistic regression.

Results: Of 891 participants, 30.6% (273 of 891) engaged in chemsex; 21.2% engaging and 16.7% not engaging in chemsex reported any NCS experiences (p=0.109).Among MSM who reported any NCS experiences, chemsex engagers reported being touched against one's will less often compared with non-engagers (22.4% vs 39.8%; p=0.036). Yet, chemsex engagers reported passing out and not remembering what happened during drug use more often (41.4% vs 8.7%; p<0.001). The level of suffering from NCS experiences did not differ between chemsex engagers and non-engagers (p=0.539); and was rated by most participants with no suffering at all or low suffering (77.1%). In the multivariable regression analyses, chemsex engagement in the past 6 months was associated with NCS (adjusted OR 1.46; 95% CI 1.01 to 2.11).

Conclusions: A substantial proportion of MSM (regardless of chemsex engagement) reported NCS in the past 5 years. In multivariate logistic regression analysis, chemsex engagement was associated with an NCS experience. Among participants who reported NCS, suffering related to NCS however, did not differ between chemsex engagers and non-engagers. Sexual healthcare professionals need to address chemsex and NCS during consultations involving MSM and refer men for specialised help if deemed necessary.