title: Effects of coexisting disorders on cognition and behavior in children with ADHD.
abstract: OBJECTIVE
  To determine whether the presence of coexisting disorders affects memory, visual-motor skills, and daily functioning in children with ADHD.
  
  
  METHODS
  Eighty-four boys and 18 girls (8 to 16 years old) participate in this study. Twenty children meet criteria for ADHD alone, 42 children for ADHD plus one other disorder, and 40 children for ADHD plus at least two other disorders (reading disability, developmental coordination disorder, oppositional defiant disorder, conduct disorder, anxiety, and depression). Children are assessed on memory and visual-motor skills. Parents complete measures of daily functioning.
  
  
  RESULTS
  No significant group differences emerge for age, socioeconomic status, or IQ. Poorer performance on tests of memory and visual-motor skills, more prevalent behavioral problems, and more impairment in everyday functioning are associated with a higher number of coexisting disorders in children with ADHD.
  
  
  CONCLUSIONS
  The presence of coexisting disorders has a significant influence on cognition and behavior of children with ADHD.
authors.affiliation: Behavioral Research Unit, Alberta Children's Hospital, Shaganappi Trail NW, Calgary, Alberta, Canada. susan.crawford@calgaryhealthregion.ca
authors.forename: Susan G
authors.initials: SG
authors.lastname: Crawford
authors.forename: Bonnie J
authors.initials: BJ
authors.lastname: Kaplan
authors.forename: Deborah
authors.initials: D
authors.lastname: Dewey
mesh_terms: D000203:Activities of Daily Living / Q000523:psychology; D000293:Adolescent; D000374:Aggression / Q000523:psychology; D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis / Q000453:epidemiology* / Q000523:psychology; D019958:Attention Deficit and Disruptive Behavior Disorders / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology; D002648:Child; D002653:Child Behavior Disorders / Q000175:diagnosis / Q000453:epidemiology* / Q000523:psychology; D003072:Cognition Disorders / Q000175:diagnosis / Q000453:epidemiology* / Q000523:psychology; D015897:Comorbidity; D003430:Cross-Sectional Studies; D004522:Educational Status; D005260:Female; D006801:Humans; D007859:Learning Disabilities / Q000175:diagnosis / Q000453:epidemiology* / Q000523:psychology; D011939:Mental Recall; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D010552:Personality Assessment / Q000706:statistics & numerical data; D011594:Psychometrics; D011596:Psychomotor Disorders / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology