title: Cognitive endophenotypes of attention deficit/hyperactivity disorder and intra-subject variability in patients with autism spectrum disorder.
abstract: Autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD) have previously been studied mainly in isolation from each other. However the two conditions may be aetiologically related and thus show overlap in aetiologically relevant functions. In order to address this question of potential aetiological overlap between ADHD and ASD, the present study set out to investigate putative endophenotypes of ADHD in N=33 typically developing (TD) children and N=28 patients with ASD that were (ASD+) or were not (ASD-) co-morbid for ADHD. With regard to both the cognitive endophenotype candidates (working memory, inhibition, temporal processing) and intra-subject variability (ISV) the pattern of abnormalities was inconsistent. Furthermore, the overall profile of ASD-TD differences was extremely similar to the pattern of differences between the ASD+ and ASD- sub-groups, suggesting that any abnormalities found were due to the comorbid ASD subgroup. This held in particular for ISV, which did not show in patients with ASD the task-general increase that is common in ADHD samples. Altogether, the present results do not support the hypothesis of aetiological overlap between ASD and ADHD.
authors.affiliation: Department of Child and Adolescent Psychiatry, University of Freiburg, Germany. Electronic address: monica.biscaldi-schaefer@uniklinik-freiburg.de.
authors.forename: M
authors.initials: M
authors.lastname: Biscaldi
authors.affiliation: Department of Child and Adolescent Psychiatry, University of Freiburg, Germany.
authors.forename: N
authors.initials: N
authors.lastname: Bednorz
authors.affiliation: Department of Child and Adolescent Psychiatry, University of Freiburg, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Weissbrodt
authors.affiliation: School of Psychology, Bangor University, United Kingdom.
authors.forename: C W N
authors.initials: CWN
authors.lastname: Saville
authors.affiliation: Department of Psychiatry and Psychotherapy, University of Freiburg, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Feige
authors.affiliation: Department of Child and Adolescent Psychiatry, Medical Faculty, University of Cologne, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Bender
authors.affiliation: Department of Child and Adolescent Psychiatry, University of Freiburg, Germany; School of Psychology, Bangor University, United Kingdom; Department of Child and Adolescent Psychiatry, Medical Faculty, University of Cologne, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Klein
mesh_terms: D001288:Attention; D001289:Attention Deficit Disorder with Hyperactivity / Q000150:complications / Q000523:psychology*; D000067877:Autism Spectrum Disorder / Q000150:complications / Q000523:psychology*; D016022:Case-Control Studies; D002648:Child; D003071:Cognition; D058068:Endophenotypes; D005260:Female; D006801:Humans; D007266:Inhibition, Psychological; D008297:Male; D008570:Memory, Short-Term
keywords: ADHD; Attention deficit/hyperactivity disorder; Autism; Autism spectrum disorders; Endophenotype; Inhibition; Intra-subject variability; Temporal processing; Working memory