Stress-related biomarkers and cognitive functioning in adolescents with ADHD: Effect of childhood maltreatment

Our study aimed to explore whether stress-related hormones (hypothalamic-pituitary-adrenal [HPA] axis hormones and prolactin) are associated with poorer cognitive functioning in adolescents with attention deficit and hyperactivity disorder (ADHD) and to test the potential moderating effect of childhood maltreatment. Seventy-six adolescents with ADHD were studied. The ADHD rating scale (ADHD-RS) and Childhood Trauma Questionnaire (CTQ) were administered. Seven cognitive tasks from the Cambridge Neuropsychological Test Automated Battery (CANTAB) were administered, and two cognitive factors (attention and memory as well as executive functioning) were identified by confirmatory factor analysis. Stress-related hormone levels were assessed at the clinic (plasma prolactin and cortisol levels and salivary cortisol levels) before cognitive testing and at home for two consecutive days (cortisol awakening response [CAR] and diurnal cortisol slope). Multiple linear regression analyses were used to explore the association between hormone levels and ADHD severity or cognitive functioning while adjusting for sex and childhood maltreatment. Regarding hormonal measurements obtained at the clinic, female sex moderated the relationship between salivary cortisol levels and executive functioning, whereas childhood maltreatment moderated the relationship between salivary cortisol levels and inattention symptoms of patients with ADHD. Prolactin levels were not associated with cognitive functioning or the severity of ADHD. Regarding HPA axis measurements performed at home, lower cortisol levels at awakening were associated with poorer executive functioning. Neither CAR nor the cortisol diurnal slope were associated with cognitive functioning or ADHD severity. Our study suggests that HPA axis hormone levels are associated with the severity of cognitive and inattention symptoms of patients with ADHD and that childhood maltreatment and sex exert distinct moderating effects depending on the symptom type.