title: Motor function and perception in children with neuropsychiatric and conduct problems: results from a population based twin study.
abstract: BACKGROUND
  Children with early symptomatic psychiatric disorders such as Attention-Deficit/Hyperactivity Disorder (ADHD) and Autism Spectrum Disorder (ASD) have been found to have high rates of motor and/or perception difficulties. However, there have been few large-scale studies reporting on the association between Conduct Disorder (CD) and motor/perception functions. The aim of the present study was to investigate how motor function and perception relate to measures of ADHD, ASD, and CD.
  
  
  METHODS
  Parents of 16,994 Swedish twins (ages nine and twelve years) were interviewed using the Autism-Tics, ADHD and other Comorbidities inventory (A-TAC), which has been validated as a screening instrument for early onset child psychiatric disorders and symptoms. Associations between categorical variables of scoring above previously validated cut-off values for diagnosing ADHD, ASD, and CD on the one hand and motor and/or perception problems on the other hand were analysed using cross-tabulations, and the Fisher exact test. Associations between the continuous scores for ADHD, ASD, CD, and the subdomains Concentration/Attention, Impulsiveness/Activity, Flexibility, Social Interaction and Language, and the categorical factors age and gender, on the one hand, and the dependent dichotomic variables Motor control and Perception problems, on the other hand, were analysed using binary logistic regression in general estimated equation models.
  
  
  RESULTS
  Male gender was associated with increased risk of Motor control and/or Perception problems. Children scoring above the cut-off for ADHD, ASD, and/or CD, but not those who were 'CD positive' but 'ADHD/ASD negative', had more Motor control and/or Perception problems, compared with children who were screen-negative for all three diagnoses. In the multivariable model, CD and Impulsiveness/Activity had no positive associations with Motor control and/or Perception problems.
  
  
  CONCLUSIONS
  CD symptoms or problems with Impulsiveness/Activity were associated with Motor control or Perception problems only in the presence of ASD symptoms and/or symptoms of inattention. Our results indicate that children with CD but without ASD or inattention do not show a deviant development of motor and perceptual functions. Therefore, all children with CD should be examined concerning motor control and perception. If problems are present, a suspicion of ADHD and/or ASD should be raised.
authors.affiliation: Child and Adolescent Psychiatry, Department of Clinical Sciences, Lund University, Baravägen 1C, SE-222 40 Lund, Sweden.
authors.forename: Peik
authors.initials: P
authors.lastname: Gustafsson
authors.affiliation: CELAM (Centre for Ethics, Law and Mental Health), University of Gothenburg, Gothenburg, Sweden ; Swedish Prison and Probation Services, R & D Gothenburg, Gothenburg, Sweden.
authors.forename: Nóra
authors.initials: N
authors.lastname: Kerekes
authors.affiliation: CELAM (Centre for Ethics, Law and Mental Health), University of Gothenburg, Gothenburg, Sweden.
authors.forename: Henrik
authors.initials: H
authors.lastname: Anckarsäter
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Paul
authors.initials: P
authors.lastname: Lichtenstein
authors.affiliation: Gillberg Neuropsychiatry Centre, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
authors.forename: Christopher
authors.initials: C
authors.lastname: Gillberg
authors.affiliation: Child and Adolescent Psychiatry, Department of Clinical Sciences, Lund University, Baravägen 1C, SE-222 40 Lund, Sweden.
authors.forename: Maria
authors.initials: M
authors.lastname: Råstam
keywords: A-TAC; Attention-Deficit/Hyperactivity Disorder; Autism Spectrum Disorder; Conduct Disorder; Motor control; Perception