Depression and Suicidal Ideation Among Men who have sex with men and Transgender Women in Chiang Mai, Thailand.

Background: Depression and suicidal ideation are common among men who have sex with men (MSM) and transgender women (TGW). Pre-exposure prophylaxis (PrEP) has become an important component of HIV prevention, but its relationship with mental health remains incompletely understood. This study compared depression and suicidal ideation/risk between PrEP users and non-users among MSM and TGW attending HIV prevention services, and identified factors associated with depression. Methods: A cross-sectional study was conducted among 150 MSM and TGW (75 PrEP users and 75 non-users) recruited from two HIV prevention clinics in Chiang Mai, Thailand Depressive symptoms were assessed using the Patient Health Questionnaire-9 (PHQ-9), and suicidal ideation/risk was assessed using the Columbia-Suicide Severity Rating Scale (C-SSRS). Group differences were compared using χ Results: PrEP users had significantly lower mean depression scores than non-users (3.80±3.46 vs. 5.96±3.76; mean difference 2.16, 95% CI: 0.99-3.33; Conclusions: Among MSM and TGW attending HIV prevention services in Chiang Mai, PrEP use was independently associated with lower depression scores, whereas suicidal ideation/risk did not differ significantly between PrEP users and non-users. Experience of discrimination was associated with higher depression scores. Although causal inferences cannot be made, the findings highlight the importance of considering mental health alongside HIV prevention services for key populations.