Psychological and biological long-term consequences of trauma in the Yazidi population displaced from Shingal after the genocide

<b>Background:</b> About a decade after the 2014 ISIS genocide in Shingal, Iraq, the effects of mass trauma and displacement continue to be felt among the Yazidi population. In particular, the long-term interplay between psychological distress and biological stress regulation remains poorly understood.<b>Objective:</b> The present study aimed to investigate the prevalence and severity of PTSD, depression, anxiety, somatic symptoms, and perceived stress among displaced Yazidi participants. It also aimed to explore how these psychological indicators relate to chronic physiological stress, as measured by hair cortisol and cortisone concentrations.<b>Method:</b> A total of 264 Yazidi adults residing in internally displaced person (IDP) camps in Duhok, Iraq, underwent structured interviews by trained psychologists. Standardized Kurdish versions of the PCL-5, HSCL-25, PHQ-15, PSS-14, and War and Adversity Checklist-26 were administered. Hair cortisol and cortisone were analyzed by liquid chromatography tandem mass spectrometry (LC-MS). Data were evaluated using multiple regressions and latent profile analysis (LPA).<b>Result:</b> Severe mental health burden was evident: 93.2% reached the cutoff for PTSD, 83.7% for anxiety, and 87.5% for depression (HSCL-25 subscales). LPA revealed three classes of PTSD symptoms - low, moderate, and high - along with four symptom classes reflecting various distress patterns. Compared to men, women exhibited significantly higher levels of psychological distress and somatic symptoms (<i>p</i> < .01, <i>d</i> = 0.60-0.70). Hair cortisol related moderately to all symptom scales (<i>r</i> = .17-.25, <i>p</i> < .01), indicating cumulative HPA axis activation. Cross-class correlations suggest that PTSD, anxiety, and depression represent, at least partly, independent symptom dimensions.<b>Conclusions:</b> Findings stress the long-lasting psychobiological effects of genocide-related trauma among Yazidi IDPs. This finding is further underlined by the integrated psychometric and biological data, which point to the urgent need for long-term, culturally sensitive, and gender-responsive interventions.