Sex and gender differences in risk factors for post-traumatic stress disorder: a systematic review and meta-analysis of prospective studies

Women are at higher risk than men for developing posttraumatic stress disorder (PTSD), but underlying mechanisms are still unclear. Comprehensive knowledge about these mechanisms is necessary to develop tailored, sex- and gender-sensitive preventive interventions. This systematic review and meta-analysis examined sex/gender-dependent risk factors, i.e., risk factors with sex/gender differences in i) vulnerability or ii) prevalence/severity, as well as sex/gender-specific risk factors, i.e., iii) risk factors present in one sex/gender only. We searched PubMed, Web of Science, PsycINFO, PsycArticles, and PSYNDEX for articles published until October 16, 2022. We included prospective studies that assessed risk factors to predict subsequent PTSD symptom severity, as measured with the Clinician-Administered PTSD scale. The primary outcomes were sex/gender stratified pooled r for sex/gender-dependent vulnerability and sex/gender-specific risk factors, and pooled OR or SMD for sex/gender-dependent risk factor prevalence/severity. We screened 17,270 records and included 117 reports from 45 studies (N=13,752) in the systematic review. Seventeen studies (N=4,257; 1,827 women, 2,430 men) were included in the meta-analysis. Regarding risk factor vulnerability, analyses revealed no significant sex/gender-differences except for acute stress symptoms, with stronger associations for men (b=0.11, SE=0.06, p<.05). Regarding risk factor prevalence/severity, women reported more severe immediate psychological stress responses (range SMD: 0.23-0.56) and more commonly had a history of mental illness (OR=1.81, 1.27-2.58). Men showed higher trauma load (SMD=-0.15, -0.29—0.01). Few women-specific and no men-specific factors were identified. Results suggest that women’s heightened immediate psychological stress response drives sex/gender disparities in PTSD symptom severity. Preventive interventions should thus target women early after trauma.