Mother's hair cortisol and symptoms of attention deficit hyperactivity disorder in her preschool child.

Children with attention deficit hyperactivity disorder (ADHD) require increased caregiver assistance and supervision, and their parents have shown high perceived parenting stress. Hence, physiological adjustment processes in the caregivers, involving the hypothalamic-pituitary-adrenal axis, seem plausible. We analyzed the association between maternal hair cortisol concentration (HCC) and symptoms of ADHD in preschool-aged children. 150 mothers of 4-5-year-old children participated in the study. To determine the HCC, the first scalp-near 3 cm hair segment was used. ADHD symptoms of the child were measured using teacher- and parent-report questionnaires and a clinical interview with the mother. When controlling for several putative confounders, teacher-reported ADHD symptoms were significantly positively associated with mothers' HCC. No associations of HCC with the mother-reported ADHD symptoms of the child emerged. It is possible that teacher-reported ADHD symptoms of the child reflect relevant ADHD symptoms more validly. As our study is the first on this issue, cross-validation is needed.