title: Does actigraphy differentiate ADHD subtypes in a clinical research setting?
abstract: OBJECTIVE
  To compare subtypes of attention-deficit/hyperactivity disorder (ADHD) (predominantly inattentive and combined types) and a comparison group on an objective measure of activity level (actigraphy).
  
  
  METHODS
  Actigraphs were worn by 64 children (49 boys, 15 girls) during a full-day clinical diagnostic assessment; 20 subjects had a diagnosis of ADHD predominantly inattentive type, 22 had ADHD combined type, and 22 were non-ADHD controls. Mean actigraph scores were calculated for two 2-hour intervals, comprising, respectively, a psychometric evaluation in the morning and the completion of a speech and language assessment and research measures in the afternoon.
  
  
  RESULTS
  There were no significant group differences in activity level in the morning session. During the afternoon session, children with ADHD were significantly more active than controls, but there were no differences between ADHD subtypes.
  
  
  CONCLUSIONS
  These data partially support specifications in the DSM-IV regarding hyperactivity in ADHD; however, they also indicate that situational and/or temporal factors may affect the degree to which hyperactivity is expressed. Furthermore, the findings contradict specifications in the DSM-IV that suggest that children with ADHD combined type should be more hyperactive than children with ADHD predominantly inattentive type.
authors.affiliation: Department of Psychiatry, Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: A V
authors.initials: AV
authors.lastname: Dane
authors.forename: R J
authors.initials: RJ
authors.lastname: Schachar
authors.forename: R
authors.initials: R
authors.lastname: Tannock
mesh_terms: D001288:Attention; D001289:Attention Deficit Disorder with Hyperactivity / Q000145:classification* / Q000175:diagnosis*; D016022:Case-Control Studies; D002648:Child; D002940:Circadian Rhythm; D015986:Confounding Factors, Epidemiologic; D005260:Female; D006801:Humans; D006948:Hyperkinesis / Q000175:diagnosis; D008297:Male; D018670:Monitoring, Ambulatory / Q000295:instrumentation*; D009043:Motor Activity; D011569:Psychiatric Status Rating Scales