title: Homogeneous Combinations of ASD-ADHD Traits and Their Cognitive and Behavioral Correlates in a Population-Based Sample.
abstract: OBJECTIVE
  Autism Spectrum Disorders (ASD) and ADHD are assumed to be the extreme manifestations of continuous heterogeneous traits that frequently co-occur. This study aims to identify subgroups of children with distinct ASD-ADHD trait profiles in the general population, using measures sensitive across both trait continua, and show how these subgroups differ in cognitive functioning.
  
  
  METHODS
  We examined 378 children (6-13 years) from a population-based sample.
  
  
  RESULTS
  Latent class analyses (LCA) detected three concordant classes with low (10.1%), medium (54.2%), or high (13.2%) scores on both traits, and two discordant classes with more ADHD than ASD characteristics (ADHD > ASD, 18.3%) and vice versa (ASD > ADHD, 4.2%). Findings suggest that ASD and ADHD traits usually are strongly related in the unaffected population, and that a minority of children displays atypical discordant trait profiles characterized by differential visual-spatial functioning.
  
  
  CONCLUSIONS
  This dissociation suggests that heterogeneity in ASD and ADHD is rooted in heterogeneity in the lower unaffected end of the distribution.
authors.affiliation: 1 Department of Cognitive Neuroscience, Donders Institute for Brain, Cognition and Behavior, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands.|2 Karakter Child and Adolescent Psychiatry University Center Nijmegen, Nijmegen The Netherlands.
authors.forename: Jolanda M J
authors.initials: JMJ
authors.lastname: van der Meer
authors.affiliation: 3 Institute for Computing and Information Science, Radboud University Nijmegen, The Netherlands.
authors.forename: Martijn G A
authors.initials: MGA
authors.lastname: Lappenschaar
authors.affiliation: 4 Department of Psychiatry, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
authors.forename: Catharina A
authors.initials: CA
authors.lastname: Hartman
authors.affiliation: 1 Department of Cognitive Neuroscience, Donders Institute for Brain, Cognition and Behavior, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands.
authors.forename: Corina U
authors.initials: CU
authors.lastname: Greven
authors.affiliation: 1 Department of Cognitive Neuroscience, Donders Institute for Brain, Cognition and Behavior, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands.|2 Karakter Child and Adolescent Psychiatry University Center Nijmegen, Nijmegen The Netherlands.
authors.forename: Jan K
authors.initials: JK
authors.lastname: Buitelaar
authors.affiliation: 2 Karakter Child and Adolescent Psychiatry University Center Nijmegen, Nijmegen The Netherlands.|5 Department of Psychiatry, Donders Institute for Brain, Cognition and Behavior, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands.
authors.forename: Nanda N J
authors.initials: NNJ
authors.lastname: Rommelse
mesh_terms: D000293:Adolescent; D001289:Attention Deficit Disorder with Hyperactivity / Q000523:psychology*; D000067877:Autism Spectrum Disorder / Q000523:psychology*; D002648:Child; D003071:Cognition; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male
keywords: ADHD; autism spectrum disorders (ASD); children