The association between “illicit drugs” (e.g., cocaine/crack, methamphetamine, gamma-hydroxybutyrate-GHB, ketamine, and ecstasy) and condomless anal sex (CAS) with casual partners is well established for sexual minority men (SMM). Recent evidence from adult SMM has indicated that marijuana is associated with the occurrence of CAS with casual partners above and beyond illicit drug use. The purpose of the current study was to evaluate associations between CAS and the use of marijuana and illicit drugs in a sample of young SMM (aged 15–24). Participants (n = 578) completed an online survey assessing demographics, current PrEP prescription, age, marijuana use, as well as drug use and sexual behavior in the past 90 days. A hurdle model simultaneously predicted the occurrence of CAS as well as the frequency of CAS among those reporting it. Illicit drug use was associated with both the occurrence (OR = 2.26; p = .01) and frequency of CAS (RR = 1.63; p = .02). In contrast, marijuana use was associated with the occurrence (OR = 1.69; p = .01), but not the frequency of CAS (RR = 1.07; p = .74). Findings mirror recent observations in large samples of adult SMM. While the effect size of marijuana is more modest than illicit drug use, marijuana does have significant and unique associations with the occurrence of CAS. HIV prevention services for young SMM may therefore benefit from assessing and addressing marijuana use in the context of HIV sexual behavior.

“非法药物”（例如，可卡因/快克、甲基苯丙胺、γ-羟基丁酸-GHB、氯胺酮和摇头丸）和与临时伴侣的无安全套肛交 (CAS) 之间的关联在性少数男性 (SMM) 中得到了很好的证实。来自成人 SMM 的最新证据表明，大麻与休闲伴侣的 CAS 发生有关，超出了非法药物使用的范围。本研究的目的是评估年轻 SMM（15-24 岁）样本中 CAS 与使用大麻和非法药物之间的关联。参与者（n = 578) 完成了一项在线调查，评估人口统计、当前 PrEP 处方、年龄、大麻使用情况以及过去 90 天内的药物使用和性行为。障碍模型同时预测了 CAS 的发生以及报告者中 CAS 的频率。非法药物使用与 CAS 的发生率 ( OR  = 2.26; p  = .01) 和频率 ( RR  = 1.63; p  = .02) 相关。相比之下，吸食大麻与发生率相关（OR  = 1.69；p  = .01），但与 CAS 的频率无关（RR  = 1.07；p = .74)。研究结果反映了最近在成人 SMM 大样本中的观察结果。虽然大麻的影响比非法药物使用更温和，但大麻确实与 CAS 的发生有显着而独特的关联。因此，针对年轻 SMM 的 HIV 预防服务可能会受益于在 HIV 性行为背景下评估和解决大麻使用问题。