Hair cortisol concentration and adolescent mental health: Insight from the Queensland Twin Adolescent Brain Project

These findings suggest that average HCC, reflecting cumulative cortisol secretion over the three months before each assessment, provides a stable measure of long-term cortisol in adolescents, although its associations with psychosocial stressors were limited in this cohort. Rather than functioning as a broadly sensitive biomarker of chronic stress, HCC may capture specific stress-related processes in certain subgroups, and its utility may depend on the type, timing, and chronicity of stress exposure.