title: [Contribution of disruptive behavior disorder to balance function of children with attention deficit hyperactivity disorder].
abstract: OBJECTIVE
  To investigate whether the likelihood of balance impairment in children with attention deficit hyperactivity disorder (ADHD) increases with the presence of disruptive behavior disorder (DBD), and whether the likelihood of co-occurring diagnosis of DBD increases in ADHD children with severer balance deficit.
  
  
  METHODS
  Three groups of 20 children each, representing pure ADHD, ADHD+DBD, and typically developing control children, were included and group matched by age and gender. Balance functions were assessed with the Balance Master in different conditions. We compared the percentages of children in each group who swayed faster than 85% of the typical control children in all conditions.
  
  
  RESULTS
  In the conditions of firm surface with eyes open (FI/EO) and eyes closed (FI/EC), and foam surface with eyes open (FO/EO) and eyes closed (FO/EC), the sway velocities of ADHD only group (0.65+/-0.26 degrees /s, 0.65+/-0.30 degrees /s, 0.95+/-0.29 degrees /s, and 1.70+/-0.49 degrees /s, respectively) were significantly higher than those of the typical control group (0.47+/-0.18 degrees /s, 0.43+/-0.19 degrees /s, 0.76+/-0.21 degrees /s, and 1.27+/-0.38 degrees /s, respectively) (P<0.05). The sway velocities of ADHD+DBD group (1.00+/-0.33 degrees /s and 1.78+/-0.66 degrees /s)were significantly higher than those of the control group only in FO/EO and FO/EC conditions (P<0.05). There was no difference between the two case groups. The percentages of children who swayed faster than 85% of normal children in the ADHD only group (50%, 50%, and 50%, respectively) were significantly higher than those of typical control group (10%, 5%, and 10%, respectively) in the conditions of FI/EO, FI/EC, and FO/EC (P<0.01); There was no difference between ADHD+DBD group and control group; In FI/EC condition, the percentage of ADHD only group (50%) was significantly higher than that of ADHD+DBD group (P<0.01).
  
  
  CONCLUSIONS
  Balance impairment in ADHD did not increase as a function of co-occurring DBD, and was due to the ADHD itself rather than to the coexisting DBD; and the probability of co-occurring DBD did not increase in ADHD with severer balance deficit.
authors.affiliation: Institute of Mental Health, Peking University, Beijing 100083, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Feng
authors.forename: Yu-feng
authors.initials: YF
authors.lastname: Wang
authors.forename: Juan
authors.initials: J
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D001289:Attention Deficit Disorder with Hyperactivity / Q000453:epidemiology / Q000503:physiopathology; D019958:Attention Deficit and Disruptive Behavior Disorders / Q000453:epidemiology / Q000503:physiopathology*; D016022:Case-Control Studies; D002648:Child; D015897:Comorbidity; D005260:Female; D006801:Humans; D008297:Male; D004856:Postural Balance