title: Prevalence and development of psychiatric disorders in childhood and adolescence.
abstract: BACKGROUND
  This longitudinal community study assessed the prevalence and development of psychiatric disorders from age 9 through 16 years and examined homotypic and heterotypic continuity.
  
  
  METHODS
  A representative population sample of 1420 children aged 9 to 13 years at intake were assessed annually for DSM-IV disorders until age 16 years.
  
  
  RESULTS
  Although 3-month prevalence of any disorder averaged 13.3% (95% confidence interval [CI], 11.7%-15.0%), during the study period 36.7% of participants (31% of girls and 42% of boys) had at least 1 psychiatric disorder. Some disorders (social anxiety, panic, depression, and substance abuse) increased in prevalence, whereas others, including separation anxiety disorder and attention-deficit/hyperactivity disorder (ADHD), decreased. Lagged analyses showed that children with a history of psychiatric disorder were 3 times more likely than those with no previous disorder to have a diagnosis at any subsequent wave (odds ratio, 3.7; 95% CI, 2.9-4.9; P<.001). Risk from a previous diagnosis was high among both girls and boys, but it was significantly higher among girls. Continuity of the same disorder (homotypic) was significant for all disorders except specific phobias. Continuity from one diagnosis to another (heterotypic) was significant from depression to anxiety and anxiety to depression, from ADHD to oppositional defiant disorder, and from anxiety and conduct disorder to substance abuse. Almost all the heterotypic continuity was seen in girls.
  
  
  CONCLUSIONS
  The risk of having at least 1 psychiatric disorder by age 16 years is much higher than point estimates would suggest. Concurrent comorbidity and homotypic and heterotypic continuity are more marked in girls than in boys.
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Duke University Medical School, Durham, NC 27710, USA. jcostell@psych.mc.duke.edu
authors.forename: E Jane
authors.initials: EJ
authors.lastname: Costello
authors.forename: Sarah
authors.initials: S
authors.lastname: Mustillo
authors.forename: Alaattin
authors.initials: A
authors.lastname: Erkanli
authors.forename: Gordon
authors.initials: G
authors.lastname: Keeler
authors.forename: Adrian
authors.initials: A
authors.lastname: Angold
mesh_terms: D000293:Adolescent; D000367:Age Factors; D002648:Child; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D001523:Mental Disorders / Q000175:diagnosis / Q000453:epidemiology* / Q000523:psychology; D020380:Needs Assessment / Q000706:statistics & numerical data; D009657:North Carolina / Q000453:epidemiology; D010552:Personality Assessment; D012306:Risk; D012737:Sex Factors; D019966:Substance-Related Disorders / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology