title: Impact of substance-induced and general medical condition exclusion criteria on the prevalence of common mental disorders as defined by the CIDI.
abstract: OBJECTIVE
  It has been previously argued that the methodology used by the Composite International Diagnostic Interview version 2.1 to assess the substance-induced and general medical condition exclusion criteria are inadequate. As a result prevalence estimates generated from epidemiological studies using this interview may be underestimated. The purpose of the current study was to examine the substance-induced and general medical condition exclusion criteria in the Australian National Survey for Mental Health and Well-being and determine the impact that they have on prevalence estimates of the common mental disorders.
  
  
  METHODS
  Data from the 1997 Australian National Survey of Mental Health and Well-being were analysed. Frequencies were generated as an indication of how many respondents believed that their psychiatric symptoms were always due to a substance or general medical condition. New DSM-IV prevalence estimates were calculated ignoring the application of the substance-induced and general medical condition exclusion criteria and compared to standard DSM-IV prevalence estimates.
  
  
  RESULTS
  The effect of the substance-induced and general medical condition exclusion criteria on final prevalence rates were minimal, with approximately a 0.1% increase when the exclusions were ignored. This equates to a relative difference ranging from no difference for generalized anxiety disorder to an increase of 12% of the base prevalence estimate for agoraphobia.
  
  
  CONCLUSIONS
  In surveys that use the Composite International Diagnostic Interview version 2.1 the substance-induced and general medical condition exclusion criteria have a minor impact on determining final case definition in the majority of mental disorders.
authors.affiliation: School of Psychiatry, University of New South Wales at St Vincent's Hospital, Sydney, New South Wales, Australia. matthews@student.unsw.edu.au
authors.forename: Matthew
authors.initials: M
authors.lastname: Sunderland
authors.forename: Tim
authors.initials: T
authors.lastname: Slade
authors.forename: Tracy M
authors.initials: TM
authors.lastname: Anderson
authors.forename: Lorna
authors.initials: L
authors.lastname: Peters
mesh_terms: D001315:Australia / Q000453:epidemiology; D039721:Diagnostic and Statistical Manual of Mental Disorders; D004608:Eligibility Determination; D006304:Health Status; D006801:Humans; D007406:Interview, Psychological; D001523:Mental Disorders / Q000175:diagnosis / Q000453:epidemiology; D015995:Prevalence; D011788:Quality of Life / Q000523:psychology; D019966:Substance-Related Disorders / Q000175:diagnosis / Q000453:epidemiology*