title: Prevalence of emotional and behavioural disorders in German children and adolescents: a meta-analysis.
abstract: BACKGROUND
  This meta-analysis aimed to determine the overall prevalence of emotional and behavioural disorders among children and adolescents in Germany, the dependence of prevalence estimates upon the methods employed and potential secular trends.
  
  
  METHODS
  Primary studies were subjected to meta-analytical analyses using a random effects model. Mean estimates of primary study effects were averaged using the precision-weighted method and were subsequently subjected to sensitivity analyses using hierarchical regression and (co-)variance analyses.
  
  
  RESULTS
  The precision-weighted average primary study prevalence for the 33 studies included was M=17.6%. The effect size primarily depended on the case definition employed, with studies applying questionnaire criteria showing, on average, lower primary study effects. Moreover, a negative relationship was found between study validity and primary study effect.
  
  
  CONCLUSIONS
  Half a century of research efforts indicate that approximately every sixth child shows signs of emotional or behavioural disorders, and conclusions regarding period effects are not robust.
authors.affiliation: Department of Child and Adolescent Psychosomatics, Center of Gynecology, Obstetrics and Paediatrics, University Hospital Hamburg-Eppendorf, Martinistrasse 52, D-20246 Hamburg, Germany. barkmann@uke.de
authors.forename: Claus
authors.initials: C
authors.lastname: Barkmann
authors.forename: Michael
authors.initials: M
authors.lastname: Schulte-Markwort
mesh_terms: D000293:Adolescent; D000342:Affective Symptoms / Q000453:epidemiology*; D002648:Child; D002675:Child, Preschool; D005858:Germany / Q000453:epidemiology; D006801:Humans; D001523:Mental Disorders / Q000453:epidemiology*; D015995:Prevalence