Lifetime trauma, recent socioeconomic stressors, and cumulative PTSD prevalence: a multi-country population-based study.

BACKGROUND: Posttraumatic stress disorder (PTSD) research has largely focused on exposure to DSM-defined traumatic events, while comparatively little attention has been paid to the role of ongoing socioeconomic stressors. Few contemporary, population-based studies have examined how lifetime trauma (e.g., physical violence) and recent socioeconomic stressors jointly relate to PTSD risk, or whether the association between socioeconomic stressors (e.g., losing a job) and PTSD differs by trauma burden among trauma-exposed individuals. METHODS: We analyzed data from the Global Social Determinants of Health Survey (2023-2024), a population-based cross-sectional survey conducted in eight countries (Brazil, France, India, Indonesia, Nigeria, the Philippines, Turkey, and the United States). Analyses were restricted to adults reporting at least one lifetime traumatic event (N = 5,525). PTSD was assessed using the Primary Care PTSD Screen for DSM-5 (PC-PTSD-5). We assessed the relationship between trauma burden, socioeconomic stressor burden, and PTSD using survey-weighted Rao-Scott chi-square tests and logistic regressions. We estimated marginal predicted probabilities for PTSD by socioeconomic stressor burden for each trauma exposure level. FINDINGS: PTSD prevalence increased from 5.1% (95% CI: 4.3%, 5.9%) among those with mild trauma to 23.9% (95% CI: 19.3%, 29.1%) among those with severe trauma. Similarly, PTSD prevalence rose from 0.6% (95% CI: 0.3%, 1.0%) among those with no recent socioeconomic stressors to 17.9% (95% CI: 15.6%, 20.4%) among those with severe exposure. The association between socioeconomic stressors and PTSD was modified by trauma burden (joint Wald test p<0.001). Among those with mild trauma, each additional stressor increased PTSD odds by 41% (OR: 1.41 [95% CI 1.32, 1.51]), while this association was attenuated among moderate (interaction OR: 0.83; combined association OR: 1.17) and severe trauma (interaction OR: 0.85; combined association OR: 1.20). PTSD prevalence was also markedly higher for specific exposures, with the largest exposed-unexposed contrasts observed for sexual violence (19.9% vs 4.6%), physical assault (17.4% vs 3.9%), forced displacement (16.2% vs 4.4%), housing insecurity (17.0% vs 4.7%), divorce or separation (14.0% vs 4.7%), and social isolation (12.2% vs 1.5%). INTERPRETATION: We found strong evidence that PTSD risk among trauma-exposed adults is shaped by both lifetime traumatic exposure and ongoing socioeconomic stressors. These findings highlight the importance of contextual adversity in shaping PTSD burden.