title: Differences in hypothalamic-pituitary-adrenal axis functioning among children with ADHD predominantly inattentive and combined types.
abstract: Some evidence suggests that the HPA axis may be dysfunctional in children with attention-deficit/hyperactivity disorder (ADHD). The aim of this study was to investigate whether a different pattern of HPA axis activity is found between the inattentive (I) and combined (C) subtypes of ADHD, in comparison with healthy control children. A total of 100 prepubertal subjects [52 children with ADHD combined type (ADHD-C), 23 children with ADHD predominantly inattentive type (ADHD-I), and 25 healthy control subjects] were studied. The effects of stress were studied by comparing cortisol responses to a psychosocial stressor, consisting of a public speaking task. Children with ADHD-I showed an elevated cortisol response to the psychosocial stressor, in contrast to children with ADHD-C who showed a blunted cortisol response to the psychosocial stressor. When a distinction was made between responders and non-responders (a subject was classified as a responder when there was an increase in cortisol reactivity), hyperactivity symptoms were clearly related to a lower cortisol reactivity to stress. The results indicate that a low-cortisol responsivity to stress may be a neurobiological marker for children with ADHD-C, but not for those with ADHD-I. Directions for future research and clinical implications are discussed.
authors.affiliation: University Center of Child and Adolescent Psychiatry Antwerp (UCKJA), ZNA Middelheim, University of Antwerp, Antwerp, Belgium. dirk.vanwest@zna.be
authors.forename: Dirk
authors.initials: D
authors.lastname: van West
authors.forename: Stephan
authors.initials: S
authors.lastname: Claes
authors.forename: Dirk
authors.initials: D
authors.lastname: Deboutte
mesh_terms: D001289:Attention Deficit Disorder with Hyperactivity / Q000145:classification / Q000175:diagnosis / Q000503:physiopathology*; D015415:Biomarkers; D002648:Child; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000032:analysis / Q000502:physiology; D007030:Hypothalamo-Hypophyseal System / Q000503:physiopathology*; D008297:Male; D010290:Parents / Q000523:psychology; D010555:Personality Inventory; D010698:Phobic Disorders / Q000378:metabolism / Q000523:psychology; D010913:Pituitary-Adrenal System / Q000503:physiopathology*; D011569:Psychiatric Status Rating Scales; D011594:Psychometrics; D012463:Saliva / Q000737:chemistry; D013060:Speech / Q000502:physiology; D013315:Stress, Psychological / Q000503:physiopathology / Q000523:psychology
chemical_list: D015415:Biomarkers; D006854:Hydrocortisone