Cannabis use highest among all groups, disparities reflect structural vulnerabilities

Differences in substance use have been reported to be higher among transgender and non-binary people (TNBP) than among their cisgender peers, although previous comparison studies are limited, especially in Europe. This study aimed to estimate and compare past-year and past-month prevalence of multiple substances between TNBP and cis people in Spain. Cross-sectional study conducted with data from 19,948 individuals aged 15-45 years, 1582 of which were TNBP. Most TNBP were recruited through Transaludes survey, a national self-administered online questionnaire on trans health that used a diversified convenience sampling. Cis participants and a small portion of the TNBP sample were recruited through EDADES, a household-based national survey on drug use with a general population random sampling design. Past 12-months and past-month use was assessed for 11 substances. Prevalence of use was calculated for trans women, cis women, trans men, cis men and non-binary people. Adjusted prevalence ratios (aPR) were estimated using Poisson regression models with robust variance, comparing trans women vs. cis women, trans men vs. cis men and non-binary people vs. cis men and women, adjusting for sociodemographic covariables. Cannabis was the most used substance in all five groups across both time periods. In the past 12 months, poppers were the second most commonly used substance among trans women, while non-medical use tranquilisers ranked second among trans men and non-binary people. Compared with cis peers, aPRs were higher for all substances among trans women and non-binary people and for most among trans men. Overall, the highest aPRs were observed in poppers use, whereas cocaine and cannabis showed smaller gaps. TNBP show a higher prevalence of substance use compared with their cis peers, particularly women. Public health policies should consider the cultural and social specificities of substance use within TNB communities in addition to structural vulnerabilities.