title: Prevalence and psychiatric comorbidity of attention-deficit/hyperactivity disorder in an adolescent Finnish population.
abstract: OBJECTIVE
  The purpose of the study was to estimate the prevalence of attention-deficit/hyperactivity disorder (ADHD) and its clinical characteristics in the Northern Finland Birth Cohort 1986.
  
  
  METHODS
  A general population Northern Finland Birth Cohort 1986 of 9,432 children followed prospectively from the early fetal period was surveyed at adolescence (ages 16-18) for ADHD behaviors. Among 6,622 respondents to the survey, a subset of 457 likely cases and controls were evaluated for ADHD and other psychiatric disorders. Chi-square and descriptive statistics were used to examine clinical characteristics of ADHD in the subset, and logistic regression was used to estimate prevalence by weighted extrapolation in the larger cohort.
  
  
  RESULTS
  The estimated prevalence of ADHD among adolescents in the Northern Finland Birth Cohort 1986 is 8.5% with a male/female ratio of 5.7:1. The distribution of ADHD subtypes among the ADHD adolescents is 28% Combined, 64% Inattentive, and 8% Hyperactive-Impulsive. A lifetime diagnosis of a broadly defined ADHD (probable or definite) had a prevalence of 18.2% with a male/female odds ratio (OR) of 3.2. This lifetime diagnosis of ADHD is significantly associated with anxiety (OR 2.4), mood (OR 2.9), and disruptive behavioral disorders (OR 17.3) in the cohort.
  
  
  CONCLUSIONS
  ADHD is a common neurobehavioral disorder among Northern Finnish adolescents and significantly associated with psychiatric comorbidity in adolescence.
authors.affiliation: Semel Institute, University of California, Los Angeles, CA 90095, USA. ssmalley@mednet.ucla.edu
authors.forename: Susan L
authors.initials: SL
authors.lastname: Smalley
authors.forename: James J
authors.initials: JJ
authors.lastname: McGough
authors.forename: Irma K
authors.initials: IK
authors.lastname: Moilanen
authors.forename: Sandra K
authors.initials: SK
authors.lastname: Loo
authors.forename: Anja
authors.initials: A
authors.lastname: Taanila
authors.forename: Hanna
authors.initials: H
authors.lastname: Ebeling
authors.forename: Tuula
authors.initials: T
authors.lastname: Hurtig
authors.forename: Marika
authors.initials: M
authors.lastname: Kaakinen
authors.forename: Lorie A
authors.initials: LA
authors.lastname: Humphrey
authors.forename: James T
authors.initials: JT
authors.lastname: McCracken
authors.forename: Teppo
authors.initials: T
authors.lastname: Varilo
authors.forename: May H
authors.initials: MH
authors.lastname: Yang
authors.forename: Stanley F
authors.initials: SF
authors.lastname: Nelson
authors.forename: Leena
authors.initials: L
authors.lastname: Peltonen
authors.forename: Marjo-Riitta
authors.initials: MR
authors.lastname: Järvelin
mesh_terms: D000293:Adolescent; D001008:Anxiety Disorders / Q000175:diagnosis / Q000453:epidemiology / Q000208:ethnology*; D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis / Q000453:epidemiology / Q000208:ethnology*; D039721:Diagnostic and Statistical Manual of Mental Disorders; D007174:Disruptive, Impulse Control, and Conduct Disorders / Q000175:diagnosis / Q000453:epidemiology / Q000208:ethnology*; D005260:Female; D005387:Finland / Q000453:epidemiology; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods; D019964:Mood Disorders / Q000175:diagnosis / Q000453:epidemiology / Q000208:ethnology*; D015995:Prevalence; D013313:Stress Disorders, Post-Traumatic / Q000175:diagnosis / Q000453:epidemiology / Q000208:ethnology*; D019966:Substance-Related Disorders / Q000175:diagnosis / Q000453:epidemiology / Q000208:ethnology*