title: [Comorbidity of attention deficit hyperactivity disorder in different age group].
abstract: OBJECTIVE
  To study age distribution of attention deficit hyperactivity disorder (ADHD) comorbidities in a relatively large sample, and exam the hypothesis of bad prognosis for ADHD.
  
  
  METHODS
  Using semi-structured clinical diagnosis interview scale, we investigated comorbidities of 1,002 ADHD children and adolescents from psychiatric out-patient clinic, and compared comorbidity frequency in 4 age groups.
  
  
  RESULTS
  The comorbidity frequencies of disruptive behavior disorder (DBD), mood disorder, tics disorder and learning disorder (LD) in different age groups of ADHD patients differed significantly (P<0.01). DBD and mood disorder in the age group of 12-14 years (124 cases,51.5%;18 cases,7.5%, respectively) were more than those in the 6-8 years group (160 cases,41.7%;9 cases,2.3%, respectively; P<0.05). And the comorbidity frequencies of the 15-17 years group were significantly higher than those in other age groups (P<0.05). Tics disorder in the 12-14 years group (50 cases,20.8%)was more than those in the two age groups of less than 12 years group (for the 6-8 years group, 51 cases,13.4%;for the 9-11 years group , 42 cases,12.5%; P<0.05).The comorbidity frequency of learning disorder grew up with age. The comorbidity frequency of the 9-11 years group (106 cases,31.5%) was significantly higher than that of the 6-8 years group (80 cases,20.9%; P<0.01); and those of both age groups more than 12 years (for the 12-14 years group, 164 cases,68.0%;for the 15-17 years group, 28 cases,70.0%) were higher than those of the two age groups of less than 12 years (P<0.01). ADHD patients without any comorbidities in the two age groups more than 12 years (for the 12-14 years group, 29 cases,12.0%;for the 15-17 years group, 4 cases,10.0%)were less than those in the two age groups of less than 12 years (for the 6-8 years group, 126 cases,32.8%;for the 9-11 years group, 110 cases,32.6%; P<0.01). These characteristics maintained in boys.
  
  
  CONCLUSIONS
  Many comorbid psychiatric disorders increase as the ADHD children become adolescents. The situation is severer in late adolescence. Therefore, ADHD children should accept appropriate treatment as early as possible, and adopt the second degree prevention actively.
authors.affiliation: Institute of Mental Health, Peking University, Beijing 100083, China.
authors.forename: Li
authors.initials: L
authors.lastname: Yang
authors.forename: Ning
authors.initials: N
authors.lastname: Ji
authors.forename: Li-li
authors.initials: LL
authors.lastname: Guan
authors.forename: Yun
authors.initials: Y
authors.lastname: Chen
authors.forename: Qiu-jin
authors.initials: QJ
authors.lastname: Qian
authors.forename: Yu-feng
authors.initials: YF
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D017677:Age Distribution; D001289:Attention Deficit Disorder with Hyperactivity / Q000453:epidemiology*; D019958:Attention Deficit and Disruptive Behavior Disorders; D002648:Child; D015897:Comorbidity; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007859:Learning Disabilities; D008297:Male; D019964:Mood Disorders; D013981:Tic Disorders