title: Diagnostic boundaries, reasoning and depressive disorder, II. Application of a probabilistic model to the OPCS general population survey of psychiatric morbidity in Great Britain.
abstract: BACKGROUND
  Reliable prevalence and risk estimation of psychiatric disorder is a cornerstone to achieving objectives in public health psychiatry. Research strategies have increasingly depended, therefore, upon the progressive evolution and refinement of diagnostic approaches designed to reflect better current knowledge concerning prognosis, course and outcome but essentially the need to improve agreement between users of the various schemes.
  
  
  METHODS
  This paper contrasts a conventional with a probabilistic approach to the diagnosis of depression based upon the OPCS United Kingdom National survey of psychiatric morbidity. The probabilistic approach, while designed to mimic current diagnostic practice in relation to the depressive disorders, naturally includes provision for the allocation of respondents on a scale of diagnostic uncertainty according to the severity of their presenting condition.
  
  
  RESULTS
  Findings are reported arising from the application of the probabilistic method to three areas of research interest in public health psychiatry, namely; an evaluation of additivity of event exposure and depressive morbidity, secondly use of the approach for investigating psychosocial models of depressive disorder and thirdly for assessing the agreement between depressive disorder when classified according to competing diagnostic schemes.
  
  
  CONCLUSIONS
  The results show application of the probabilistic approach to provide a firm basis for achieving gains in both the stability and precision of risk profile estimation for depressive conditions.
authors.affiliation: MRC Biostatistics Unit, University of Cambridge.
authors.forename: P G
authors.initials: PG
authors.lastname: Surtees
authors.forename: N W
authors.initials: NW
authors.lastname: Wainwright
authors.forename: W R
authors.initials: WR
authors.lastname: Gilks
authors.forename: T S
authors.initials: TS
authors.lastname: Brugha
authors.forename: H
authors.initials: H
authors.lastname: Meltzer
authors.forename: R
authors.initials: R
authors.lastname: Jenkins
mesh_terms: D000293:Adolescent; D000328:Adult; D000465:Algorithms; D003627:Data Interpretation, Statistical; D003866:Depressive Disorder / Q000145:classification / Q000175:diagnosis* / Q000453:epidemiology* / Q000209:etiology; D006306:Health Surveys; D006801:Humans; D008016:Life Change Events; D016015:Logistic Models; D008370:Manuals as Topic / Q000592:standards; D008875:Middle Aged; D008960:Models, Psychological; D016017:Odds Ratio; D015995:Prevalence; D011336:Probability; D011570:Psychiatry / Q000379:methods* / Q000592:standards; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D012944:Social Support; D012959:Socioeconomic Factors; D013315:Stress, Psychological / Q000453:epidemiology; D006113:United Kingdom / Q000453:epidemiology