Testing for stress sensitization to war exposure in adult Ukrainian refugees using latent classes of adverse childhood experiences

Refugees of war are at high risk of exposure to war-related potentially traumatic events (PTEs) and the development of posttraumatic stress disorder (PTSD). The stress sensitization hypothesis posits that adverse childhood experiences (ACEs) can sensitize individuals to the stress of PTEs in adulthood. This study examined how ACEs might sensitize refugees to war exposure in a sample of 3,486 Ukrainian refugees. We identified four latent classes of ACEs: low exposure (57.4%), household dysfunction (21.5%), maltreatment (16.7%), and high exposure (4.4%). These classes were used in a logistic regression model to test for associations with PTSD, and an ACE Class x War Exposure interaction term was used to test for stress sensitization. Female gender, odds ratio (OR) = 1.99, 95% confidence interval (CI) [1.58, 2.49]; war exposure, OR = 1.55, 95% CI [1.30, 1.83]; and all ACE classes, ORs = 1.14-2.84, were significantly associated with PTSD, whereas we found no effects of stress sensitization. The lack of stress sensitization effects in our analysis might have been caused by uniformly high stress levels in this refugee sample, as well as the broadly defined war exposure measure we used. Future research should aim to assess whether certain types or intensities of exposure better reveal sensitization effects.