Preconception mental health (Healthy Life Trajectories Initiative): Identifying factors associated with probable anxiety and depression among young women living in urban-poor South Africa.

Mental health disorders affect millions worldwide, with socially vulnerable youth in urban environments disproportionately affected. South Africa (SA) remains one of the most inequitable countries, and specific pathways linking poverty to mental health remains unclear. This cross-sectional study analysed baseline data from the Bukhali trial in Soweto, SA part of the global Healthy Life Trajectories Initiative (HeLTI). Young women (n = 7735) completed surveys with physical assessments covering sociodemographic, household-level and behavioural-level factors, and mental health. Among the women, 12.6% reported anxiety, 15.8% reported depression, and 9.7% experienced both. Hazardous alcohol use (20.0%) and poor sleep (55.5%) were commonly reportedly behavioural factors among these women. Being in a committed relationship reduced the odds of reporting anxiety and depression (OR ≥0.66), while childhood adversity, hazardous alcohol use, and poor sleep increased the odds (OR ≥1.29). Moderate to severe anxiety greatly increased the risk of depression (OR 32.20). In the comorbid model, while being in a committed relationship remained protective (OR 0.67), childhood adversity and poor sleep quality was associated with substantial risk (OR ≥1.31) of this co-morbidity. In a gSEM constructed a priori, significant direct associations were found for poverty (measured by household socioeconomic status) on alcohol use (p = 0.015), childhood adversity on mental health (p < 0.001), and committed relationship on anxiety (p < 0.001). Mediation analysis revealed that poverty affected anxiety partially through poor sleep (54.2%), and fully via depression (86.9%), and affected depression fully via sleep (43.7%). Childhood adversity associated with depression partially via anxiety (79.4%), sleep (31.3%), and alcohol use (14.2%), and anxiety through depression (88.6%) and sleep (42.2%). In conclusion, childhood adversity, poverty and behavioural factors co-occur, and are collectively associated with elevated symptoms of anxiety and depression among young women in urban-poor settings. While tackling structural inequalities is critical, strengthening mental health support networks in these settings could aid women.