title: Mental health disorders among individuals with mental retardation: challenges to accurate prevalence estimates.
abstract: OBJECTIVE
  The objectives of this literature review were to assess current challenges to estimating the prevalence of mental health disorders among individuals with mental retardation (MR) and to develop recommendations to improve such estimates for this population.
  
  
  METHODS
  The authors identified 200 peer-reviewed articles, book chapters, government documents, or reports from national and international organizations on the mental health status of people with MR. Based on the study's inclusion criteria, 52 articles were included in the review.
  
  
  RESULTS
  Available data reveal inconsistent estimates of the prevalence of mental health disorders among those with MR, but suggest that some mental health conditions are more common among these individuals than in the general population. Two main challenges to identifying accurate prevalence estimates were found: (1) health care providers have difficulty diagnosing mental health conditions among individuals with MR; and (2) methodological limitations of previous research inhibit confidence in study results.
  
  
  CONCLUSIONS
  Accurate prevalence estimates are necessary to ensure the availability of appropriate treatment services. To this end, health care providers should receive more training regarding the mental health treatment of individuals with MR. Further, government officials should discuss mechanisms of collecting nationally representative data, and the research community should utilize consistent methods with representative samples when studying mental health conditions in this population.
authors.affiliation: Department of Epidemiology and Public Health, Yale University School of Medicine, New Haven, CT, USA. bkerker@health.nyc.gov
authors.forename: Bonnie D
authors.initials: BD
authors.lastname: Kerker
authors.forename: Pamela L
authors.initials: PL
authors.lastname: Owens
authors.forename: Edward
authors.initials: E
authors.lastname: Zigler
authors.forename: Sarah M
authors.initials: SM
authors.lastname: Horwitz
mesh_terms: D000328:Adult; D015982:Bias; D002648:Child; D015897:Comorbidity; D003625:Data Collection / Q000379:methods / Q000592:standards; D003627:Data Interpretation, Statistical; D006304:Health Status; D006306:Health Surveys; D006801:Humans; D008607:Intellectual Disability / Q000150:complications*; D001523:Mental Disorders / Q000150:complications / Q000175:diagnosis / Q000453:epidemiology; D008603:Mental Health; D020380:Needs Assessment; D011159:Population Surveillance / Q000379:methods; D015995:Prevalence; D015203:Reproducibility of Results; D012107:Research Design / Q000592:standards; D012307:Risk Factors; D012720:Severity of Illness Index