Hair cortisol and psychiatric symptomatology in children; outcomes of group CBT.

The associations between hair cortisol concentration (HCC), a biomarker of chronic stress, and behavior and sleep disturbance symptoms have not been studied in children with psychiatric disorders. While cognitive behavioral therapy (CBT) has proven effective in treating psychiatric symptoms in children, its potential biological implications as determined by HCC have not been investigated. We explored associations between HCC, behavior and sleep disturbance symptoms, and different diagnostic groupings (depression/anxiety, ADHD, or other types of psychiatric disorders) in clinician-diagnosed 6-12-year-old children (n = 100) with mixed psychiatric disorders and comorbidities. In addition, we examined whether group CBT led to changes in HCC, behavior symptoms, and sleep disturbance symptoms and whether any fluctuations in HCC levels were associated with potential symptom change. We collected data on HCC, internalizing and externalizing symptoms (The Spence Children's Anxiety Self-Report, Child Behavior Checklist, and Teacher Report Form), and sleep disturbance symptoms (The Sleep Disturbance Scale for Children) at three time points (baseline, post-treatment, and seven-month follow-up). Baseline HCC was not associated with behavior or sleep disturbance symptoms, whereas behavior and sleep disturbance symptoms were mutually correlated. No changes in HCC levels were observed with group CBT. Moreover, potential variations in HCC levels over the course of the study did not appear to be associated with behavior symptom relief after group CBT. Our findings suggest that HCC may not be a methodologically relevant biomarker of behavior or sleep disturbance symptoms in children with diverse psychiatric disorders.