Analysis of hair cortisol concentration (HCC) corroborates the beneficial impact of a novel intervention in adolescents affected by war and displacement, new research shows.
A multinational team of investigators analyzed HCC in Syrian refugee and Jordanian nonrefugee children and adolescents (aged 12 to 18 years) living in northern Jordan near the Syrian border. The study subjects were participants in Advancing Adolescents, an 8-week program implemented by the global humanitarian organization Mercy Corps.
Hair samples were collected immediately before and immediately after the intervention and during a follow-up that occurred 11 months after the initial sampling.
The researchers' intervention decreased HCC by a third, corroborating participants' self-reports of improved psychosocial well-being.
"Our research demonstrates the utility of using stress markers for tracking physiological changes in response to interventions," lead researcher Catherine Panter-Brick, DPhil, professor of anthropology, health, and global affairs, Yale University, New Haven, Connecticut, told Medscape Medical News.
"It also provides evidence beyond self-report of the effectiveness of the intervention itself in reducing stress in this population," she added.
The study was published online December 26 in Psychoneuroendocrinology.
Hair Is a "Stress Diary"
Stress biomarkers, such as HCC, "have the potential to provide a biological signature of adverse experiences," the authors write.
Few studies have "robustly examined" the trajectories of cortisol production in populations affected by war and forced displacement. Moreover, studies of the biological stress response in war and disaster settings have "rested largely upon observational or case-control studies rather than discrete interventions."
The researchers undertook the study to investigate whether stress biomarkers might be used to track the impact of interventions targeting improvements in mental health and psychosocial well-being in humanitarian crises.
Accordingly, they set out to study whether the use of HCC could "provide a long-term marker of the endocrine stress response and a useful measure of integrated HPA [hypothalamic-pituitary-adrenal] activity, pre- and post-intervention."
The study also examined the impact of the Advancing Adolescents program in promoting the "capacities for the mediation of extreme and prolonged stress in vulnerable adolescent populations."
"Hair is a 'stress diary' that tracks the cumulative effects of stress, and we chose it instead of salivary cortisol for several reasons, one of which is that salivary cortisol measures reactivity, while hair cortisol measures chronicity," said Dr Panter-Brick.
The researchers collected data from a sex-balanced sample of 733 children and adolescents (411 Syrian, 322 Jordanian) and compared the impact of the Advancing Adolescents program on participants relative to wait-listed control persons.
Syrian and Jordanian field-workers completed the survey and biomarker collection data, and local hairdressers were engaged to collect hair samples as a component of a professional haircut given as a reward for participation.
Lifetime trauma events were assessed with the Trauma Event Checklist, which is a screening tool based on the Harvard Trauma Questionnaire and the Gaza Traumatic Event Checklist.
Resilience was measured through a 12-item Arabic version of the Child and Youth Resilience Measure. Fearlike feelings were measured through the Human Insecurity scale, and the Perceived Stress Scale was used to assess past-month feelings of being upset, nervous, angered, lacking control, or being unable to cope.
The Children's Revised Impact of Event Scale was used to assess posttraumatic stress reactions.
Expected, Unexpected Results
The researchers found that Syrian refugees had been exposed to "significant trauma," as compared with Jordanians, with an average of 6.25 vs 1.06 (SD = 3.25 and 1.68 respectively; P < .001) lifetime traumas.
Syrian refugees had higher levels of symptoms of posttraumatic stress disorder (PTSD), as well as higher levels of perceived stress and insecurity (P < .001), as compared to Jordanian nonrefugees.
Participants who met criteria for PTSD had higher baseline HCC than those who did not have PTSD (M = 0.86 [SD 0.34] and M = 0.79 [SD 0.39], respectively).
Three trajectories of HCC emerged: hypersecretion, medium secretion, and hyposecretion of cortisol (9.6%, 87.5%, and 2.9% of the cohort, respectively).
For every percentage point increase in levels of fear and insecurity, participants were 0.02 times more likely to have a trajectory of hypersecretion (95% confidence interval [CI], 1.00 - 1.03; P = .01).
For each additional symptom of posttraumatic stress, they were 0.07 times less likely to show hyposecretion (95% CI: .89 - .98; P = .01).
"Stronger posttraumatic reactions were associated with a pattern of within-individual cortisol dysregulation and medium secretion," the authors note.
"Insecurity and posttraumatic stress symptoms predict different patterns of cortisol production over time," they add.
When other variables were held constant, the researcheers found that females were more likely than males to be in the hypersecretion category (B = -1.57; SE = .31; 95% CI, .11 - .39; P < .001).
The HCC-lowering benefits of the intervention were similar for all participants, whether male or female, Syrian or Jordanian, who had been exposed to high or low levels of trauma, or adolescents who had different levels of insecurity, stress, or posttraumatic reactions (P > .05).
Participation in the intervention decreased cortisol by 15.2% for the hypersecretion group and 43.2% for the medium-secretion group.
By contrast, the intervention increased HCC for youth with hyposecretion by 59.7% (95% CI, .22 - 1.16; P = .004) relative to wait-listed control persons.
Sex, resilience, and PTSD were not found to significantly influence the strength or direction of responses to the intervention.
Dr Panter-Brick used the term "unexpected" to describe the finding that the intervention lowered HCC in the hypersecretion group but raised it in the hyposecretion group. He noted that the finding suggests that the beneficial impact of the intervention might be due to cortisol regulation.
"There are two physiological responses to stress, hyperarousal and hypoarousal," she said.
"In hyperarousal, the person becomes very vigilant, while in hypoarousal, responses are blunted, which may correspond respectively to hypersecretion and hyposecretion of cortisol," she said.
Hyperarousal is more often associated with recent stress, and hypoarousal is more often associated with chronic stress, she noted.
"We have to tease these factors out and can't generalize or assume a one-to-one relationship between cortisol and stressors, since the response depends on a variety of factors," she emphasized.
The findings validate the Advancing Adolescents intervention.
"I was surprised by the dramatic effect, namely, that a third of the cohort had stress levels regulated or downregulated, which was quite a lovely finding to have," she said.
Moving the Needle
Commenting on the study for Medscape Medical News, Theresa S. Betancourt, ScD, Salem Professor in Global Practice, and director, Research Program on Children and Adversity, Boston College School of Social Work, in Massachusetts, called the study "very innovative."
"It is the first known study of its kind to prospectively examine associations between HCC and self-reports of stress, insecurity, posttraumatic stress reactions, and lifetime trauma and to test the impact of an 8-week stress attunement intervention on these outcomes," she said.
The study "makes an important contribution to the field by demonstrating that the collection of certain stress biomarkers is possible in research during an active humanitarian emergency and linking response to an intervention not only to self-report surveys but also to objective biomarkers via HCC."
The study has important implications for clinicians working with war-affected populations, "as it points to the variability that can underscore the trauma response," thereby allowing more individualized interventions.
Dr Panter-Brick noted that study participants and their families wanted their story to be told to the world.
The research was conducted with Rana Dajani, PhD, of the Department of Biology and Biotechnology, Hashemite University, Zarqa, Jordan, and the Radcliffe Institute for Advanced Study, Harvard University. Dr Dajani is a Jordanian/Syrian scientist who "has the trust of the population."
"Our work together has moved a needle in terms of evaluation in the humanitarian world," she said.
The research was funded by Elrha's Research for Health in Humanitarian Crises Programme, which is funded equally by the Wellcome Trust and the UK government. Dr Panter-Brick and Dr Betancourt have disclosed no relevant financial relationships.
Psychoneuroendocrinology. Published online December 26, 2017. Abstract
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Cite this: Cortisol in Hair a Biomarker for Chronic Stress, Treatment Efficacy - Medscape - Jan 19, 2018.