Developmental Trajectory of Hair Cortisol Concentrations Across Childhood

The study analyzed the developmental trajectory of hair cortisol concentrations (HCC) in children from newborns to 7 years old, involving 212 mother-child pairs. Results showed that HCC mean values and standard deviations decrease with age, with significant differences observed from newborns to 3 years, but stabilization from ages 4 to 7. The higher cortisol levels in early childhood may be linked to organ growth and development, while the decrease over time suggests maturation of the stress system. These findings are crucial for clinicians and researchers working with HCC in pediatric populations.