Elevated concentrations of the stress hormone cortisol in hair could potentially predict depressive symptoms in teenagers, but this relationship is not necessarily linear, new research suggests.
A study that included more than 400 adolescents linked cortisol levels to a greater risk for depression. Investigators also found a relationship between lower cortisol levels and other psychiatric conditions.
“The most surprising finding actually was that both the cortisol levels at the low end and the high end of the distribution were correlated with depressive symptoms,” lead author Jodi Ford, PhD, RN, associate professor and director of the Stress Science Lab at the Ohio State University College of Nursing in Columbus, told Medscape Medical News.
The findings were published online in Psychoneuroendocrinology.
First Study of Its Kind
Major depression is a risk factor for suicide, which is the second leading cause of death among American youth aged 11 to 17. Nearly one in 8 youths in the US reported a major depressive episode in 2016, a rate that has been increasing over the last decade.
Better biomarkers may improve identification and management of adolescent depression.
Cortisol is a steroid hormone that is continuously released by the hypothalamic–pituitary–adrenal axis (HPA) into the circulatory system. Hair can provide a retrospective and longer-term measure of the mean cortisol level, compared to saliva, which needs to be collected more frequently, said Ford.
As reported by Medscape Medical News, previous research has evaluated hair cortisol as a potential marker of chronic stress, childhood trauma and poor cognition, and even treatment efficacy.
However, previous studies showed mixed evidence on the relationship between hair cortisol and depressive symptoms. The current study, investigators note, is the first to examine cortisol levels as a predictor for depression in youth.
The study included a community sample of 432 teenagers (aged 11 to 17 years old) from the 1401 participants in the ongoing Adolescent Health and Development in Context (AHDC) trial.
The AHDC was a longitudinal cohort study investigating the impact of social and spatial exposures on the health of a diverse group of adolescents in Franklin County, Ohio.
Investigators assessed depressive symptoms using a 10-item short-form version of the Center for Epidemiologic Studies-Depression (CESD) scale.
The questionnaire asked the teens to describe their depressive symptoms experienced in the prior week and provided four possible responses that ranged from “rarely/none of the time/1 day” to “most/all of the time/5-7 days.” As the positive-affect symptoms were reverse-coded, higher scores indicated more depressive symptoms.
After asking the teenagers about their hair care practices, including washing frequency, chemical treatments, and product use, the researchers used thinning shears to cut up to 3 cm of hair samples close to the scalp. They then assayed the hair samples to measure mean cortisol levels.
Study control measures included youth-reported age, race and ethnicity, hair care practices, and pubertal development. Caregiver-reported measures included marital status, annual household income, youth use of selected serotonin reuptake inhibitors (SSRIs), and if the youth was ever diagnosed with depression.