Hair cortisol concentrations among youth in Ukraine: Associations with war experiences and post-traumatic-stress symptoms.

[OBJECTIVE] To explore relations between cortisol response measured by hair cortisol concentrations (HCC), war exposure (e.g., air alarms and explosions), and psychological distress for youth living in Ukraine during the current invasion.

[METHODS] 221 youth (Mage = 18.9 years; 20 % male) living in 5 regions of Ukraine from November 2023-March 2024 provided hair samples to assess HCC and self-report data measuring post-traumatic stress symptoms (PTS symptoms). Youth's region of residence was matched to air alarm and explosion data.

[RESULTS] Consistent with prior research examining HPA axis activity during chronic stress, we found that exposure to more air alarms and explosions were each associated with lower HCC. Contrary to our hypotheses, we found no relation between HCC and PTS symptoms.

[CONCLUSIONS] Our results suggest that youth experiencing chronic war exposure may adapt by down-regulating their cortisol production, which could generate long-term health problems such as immune dysregulation or increased inflammatory activity.