Lower right insular thickness is associated with more severe post-traumatic stress disorder symptoms among Ukrainian refugees

Introduction: Refugees often face traumatic experiences and ongoing post-migration stressors, increasing their risk for post-traumatic stress disorder (PTSD). However, no study to date has examined whether cortical thickness moderates the relationship between post-migration living difficulties (PMLDs) and PTSD symptoms. This study aimed to investigate if cortical thickness underlies vulnerability or resilience to PTSD in war-affected refugees. Methods: A total of 60 Ukrainian refugees (aged 27.8 ± 6.1 years, 81.7% females), who arrived in Poland after the 2022 Russian invasion, underwent assessment of behavioral and psychopathological characteristics together with MRI structural neuroimaging. Results: Refugees with PTSD had significantly reduced cortical thickness in the right insula compared to those without PTSD. They also reported higher levels of PMLDs and exposure to traumatic events. Logistic regression analyses revealed that decreased right insular cortex thickness and a greater number of traumatic experiences were associated with higher odds of PTSD symptoms after adjustment for age, sex, education, cigarette smoking status, and the current history of somatic diseases. A significant positive association of the interaction between the number of traumatic experiences and right insular cortex thickness with the odds of PTSD symptoms was also observed. Discussion: The findings imply that cortical thickness of the right insula might be associated with more severe PTSD symptoms among individuals exposed to traumatic experiences.