Hair Cortisol Outperforms Questionnaires in Measuring Ukraine War Stress

Research presented on March 19, 2026, at the annual meeting of the American Association of Biological Anthropologists in Denver indicates that measuring cortisol in hair may be a more effective way to identify chronic stress in war refugees than using standard questionnaires.

The findings come from a study of approximately 300 women and children who fled to Poland following the February 2022 Russian invasion of Ukraine. The research was led by Grazyna Jasienska, a human biologist at Jagiellonian University in Kraków, Poland.

Limitations of Standard Stress Assessments

Identifying individuals at the highest risk for long-term mental health issues—such as anxiety, depression, and post-traumatic stress—has been difficult because common questionnaires are often not specific to refugee populations.

In Jasienska’s study, adults completed a questionnaire designed to assess stress in unpredictable and overwhelming situations. Similar questionnaires were completed for younger children, while older children responded independently.

The survey results suggested that stress levels were nearly identical between individuals who were indirectly exposed to the war or lived in Ukrainian-controlled areas and those who had been directly exposed to combat or fled Russian-controlled areas.

The Role of Hair Cortisol Concentrations

While the questionnaires showed little difference, hair samples revealed a different biological reality. Cortisol is a hormone that helps the body respond to danger, but it builds up in hair over time.

Analysis of hair snippets can provide a biological snapshot of a person’s stress levels over the previous three months, offering a more objective measure of cumulative stress than self-reported data.

Biological Adaptation in Active War Zones

Additional research conducted by Duke University’s Center for Child and Family Policy examined the biological stress responses of youth still living within Ukraine. Lead author Ann Skinner and co-authors Jennifer Godwin and Emmy Reilly collected hair samples and survey data from 221 university students between November 2023 and March 2024.

This study paired hair cortisol concentrations (HCC) with regional data on explosions and air alarms. The researchers found that students who experienced more air alarms and explosions over the prior 90 days tended to have lower hair cortisol levels.

This phenomenon is known as down-regulation. When danger becomes constant, the body’s stress system may recalibrate and reduce cortisol production. While this shift may protect the body from the immediate damage of high cortisol, it can lead to long-term health complications.

• Immune dysregulation
• Increased inflammatory activity
• Fatigue
• Other long-term health concerns

Disconnect Between Biology and Perception

The Duke University study also found no significant link between HCC and self-reported post-traumatic stress (PTS) symptoms. This suggests that a young person’s reported distress over a single week may not match the biological stress markers recorded in their hair over three months.

These combined findings highlight a critical gap in how chronic stress is measured in conflict zones. While refugees may show distinct biological markers of stress after fleeing, those remaining in active war zones may exhibit a biological “flattening” or down-regulation of the stress response despite ongoing exposure to trauma.