title: Differences in HPA-axis and heart rate responsiveness to psychosocial stress in children with autism spectrum disorders with and without co-morbid anxiety.
abstract: Children and adolescents with autism spectrum disorder (ASD) have much higher rates of anxiety disorders relative to their typically developing peers. However, there have been few attempts to investigate what physiological parameters may be associated with this elevated rate of anxiety. Therefore, this study investigated the physiological correlates of anxiety in ASD, with a focus on whether measures of heart rate and cortisol responsiveness to psychosocial stress differentiate those participants with ASD with and without a co-occurring anxiety disorder. A total of 75 male participants aged 10-16 years with normal intellectual ability underwent a psychosocial stress test. The participants included healthy controls (n=23), ASD only (ASD; n=20) and ASD with a comorbid anxiety disorder (ASDanx; n=32). Heart rate, heart rate variability and salivary cortisol were compared by fitting a piecewise regression model to examine baseline levels and change over time within and between the rest, stress and recovery phases of the stress test. The ASDanx group had different response patterns from both the ASD and control groups. The ASDanx group was characterized by a blunted cortisol and heart rate response to psychosocial stress. Furthermore, in the ASDanx group, reduced heart rate and cortisol responsiveness were significantly related to increased anxiety symptoms. This is the first study to report a possible physiological basis for co-occurring anxiety disorders in children and adolescents with ASD. It is possible that a non-adaptive physiological response to psychosocial stress may be related to the high prevalence of co-occurring anxiety disorders in people with ASD.
authors.affiliation: King's College London, Institute of Psychiatry, Department of Child & Adolescent Psychiatry, London SE5 8AF, United Kingdom. Electronic address: matthew.hollocks@kcl.ac.uk.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Hollocks
authors.affiliation: King's College London, Institute of Psychiatry, Department of Psychology, London SE5 8AF, United Kingdom; University of Sydney, Faculty of Health Sciences, NSW 2141, Australia.
authors.forename: Patricia
authors.initials: P
authors.lastname: Howlin
authors.affiliation: King's College London, Institute of Psychiatry, Department of Psychological Medicine, London SE5 8AF, United Kingdom.
authors.forename: Andrew S
authors.initials: AS
authors.lastname: Papadopoulos
authors.affiliation: King's College London, Institute of Psychiatry, Department of Biostatistics, London SE5 8AF, United Kingdom.
authors.forename: Mizanur
authors.initials: M
authors.lastname: Khondoker
authors.affiliation: King's College London, Institute of Psychiatry, Department of Child & Adolescent Psychiatry and Biomedical Research Centre for Mental Health, London SE5 8AF, United Kingdom.
authors.forename: Emily
authors.initials: E
authors.lastname: Simonoff
mesh_terms: D000293:Adolescent; D001007:Anxiety / Q000150:complications / Q000503:physiopathology* / Q000523:psychology*; D002648:Child; D002659:Child Development Disorders, Pervasive / Q000150:complications / Q000503:physiopathology* / Q000523:psychology*; D003142:Communication; D006339:Heart Rate; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism; D007030:Hypothalamo-Hypophyseal System; D008297:Male; D011569:Psychiatric Status Rating Scales; D012463:Saliva / Q000378:metabolism; D012931:Social Environment; D013315:Stress, Psychological / Q000503:physiopathology*
chemical_list: D006854:Hydrocortisone
keywords: Autistic disorder; Cortisol; Developmental disorders; Emotion; Mood disorders