title: A clinical study of attention-deficit/hyperactivity disorder in preschool children--prevalence and differential diagnoses.
abstract: OBJECTIVE
  We aimed to examine (1) the prevalence and characteristics of ADHD in preschool children, and (2) differential diagnoses among children who display symptoms of inattention and hyperactivity-impulsivity in early childhood.
  
  
  METHODS
  The participants were children living in Kanie-cho, in Japan's Aichi Prefecture, who underwent their age 5 exams at the municipal health center between April 2009 and March 2011. We first extracted children who were observed to be inattentive or hyperactive-impulsive during their age 5 exams and considered as possibly having ADHD. We conducted follow-ups with these children using post-examination consultations, visits to preschools, and group rehabilitation. The results of the age 5 exams were combined with behavior observations and interview content obtained during subsequent follow-ups. A child psychiatrist and several clinical psychologists discussed these cases and made a diagnosis in accordance with the DSM-IV-TR.
  
  
  RESULTS
  91 (15.6%) of the 583 children selected were considered as possibly having ADHD; we were able to conduct follow-ups with 83 of the 91 children. Follow-up results showed that 34 children (5.8% of all participants) remained eligible for a diagnosis of ADHD. Diagnoses for the remaining children included: pervasive developmental disorders (six children, or 6.6% of suspected ADHD children), intellectual comprehension problems (four children, or 4.4%), anxiety disorders (seven children, or 7.7%), problems related to abuse or neglect (four children, or 4.4%), a suspended diagnosis for one child (1.1%), and unclear diagnoses for 29 children (31.9%).
  
  
  CONCLUSIONS
  ADHD tendencies in preschool children vary with changing situations and development, and the present study provides prevalence estimates that should prove useful in establishing a diagnostic baseline.
authors.affiliation: Center for Developmental Clinical Psychology and Psychiatry, Nagoya University, Nagoya, Japan. Electronic address: nomura@cc.nagoya-u.ac.jp.
authors.forename: Kenji
authors.initials: K
authors.lastname: Nomura
authors.affiliation: Center for Developmental Clinical Psychology and Psychiatry, Nagoya University, Nagoya, Japan.
authors.forename: Kaori
authors.initials: K
authors.lastname: Okada
authors.affiliation: Kanie Health Center, Aichi, Japan.
authors.forename: Yoriko
authors.initials: Y
authors.lastname: Noujima
authors.affiliation: Kanie Health Center, Aichi, Japan.
authors.forename: Satomi
authors.initials: S
authors.lastname: Kojima
authors.affiliation: Center for Developmental Clinical Psychology and Psychiatry, Nagoya University, Nagoya, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Mori
authors.affiliation: Center for Developmental Clinical Psychology and Psychiatry, Nagoya University, Nagoya, Japan.
authors.forename: Misuzu
authors.initials: M
authors.lastname: Amano
authors.affiliation: Graduate School of Education, Naruto University of Education, Naruto, Japan.
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Ogura
authors.affiliation: Faculty of Humanities and Social Sciences, Shizuoka University, Shizuoka, Japan.
authors.forename: Chie
authors.initials: C
authors.lastname: Hatagaki
authors.affiliation: Center for Developmental Clinical Psychology and Psychiatry, Nagoya University, Nagoya, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Shibata
authors.affiliation: Center for Developmental Clinical Psychology and Psychiatry, Nagoya University, Nagoya, Japan.
authors.forename: Rie
authors.initials: R
authors.lastname: Fukumoto
mesh_terms: D001008:Anxiety Disorders / Q000175:diagnosis / Q000453:epidemiology; D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis* / Q000453:epidemiology* / Q000534:rehabilitation; D002649:Child Abuse / Q000706:statistics & numerical data; D002659:Child Development Disorders, Pervasive / Q000175:diagnosis / Q000453:epidemiology; D002675:Child, Preschool; D003937:Diagnosis, Differential; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008607:Intellectual Disability / Q000175:diagnosis / Q000453:epidemiology; D007406:Interview, Psychological; D007564:Japan / Q000453:epidemiology; D008297:Male; D015995:Prevalence; D012574:Schools
keywords: Attention-deficit/hyperactivity disorder (ADHD); Differential diagnoses; Preschool children; Prevalence