The prevalence of suicidal thoughts and behaviours and social and clinical correlates in Cape Town: a cross-sectional study.

Background Suicidal thoughts and behaviours (STBs) are traditionally framed as arising from mental health problems, however, emerging evidence highlights the importance of social determinants in contributing to suicide risk. We examined STBs and their socioeconomic, psychosocial and clinical correlates in two peri-urban communities in Cape Town.Methods We conducted psychiatric diagnostic interviews (MINI) at three public-sector facilities (2023-2024). Adults aged ≥18 years, with and without HIV, were recruited in a 2:1 ratio. We examined STB prevalence and associations between past 30-day suicidal ideation and sociodemographic factors, violence exposure, perceived stress, mental disorders, and HIV.Results We enrolled 613 participants (63.9% female; 65.4% HIV-positive; median age 39). The prevalence of past 30-day suicidal ideation was 14.0%, while 22.2% reported a lifetime suicide attempt. Odds of past 30-day ideation were higher in females (OR 2.07, 95% CI 1.21-3.54), those who had experienced violence in their community (1.93, 1.09-3.41) or family (3.00, 1.55-5.81), those with high perceived stress (4.57, 1.93-10.81), and in those with depression (6.62, 3.39-12.92), post-traumatic stress disorder (6.69, 2.97-15.04), and an alcohol use disorder (2.27, 1.23-4.17). Associations with high perceived stress and community violence persisted after adjustment for mental disorders. HIV and other sociodemographic factors were not significantly associated.Conclusion STB prevalence was high in peri-urban communities in Cape Town and strongly associated with mental disorders, violence exposure, and perceived stress. These findings underscore the role of structural and psychosocial stressors in shaping suicide risk in low-income communities.