title: Diagnosis of schizophrenia: reliability of an operationalized approach to 'praecox-feeling'.
abstract: BACKGROUND
  H.C. Rumke coined the term 'praecox-feeling' to denote a specific unease experienced by the clinician reflecting the 'impossibility of empathy' and 'lack of exchange of affect' that has been reported to occur early on when examining schizophrenia patients. There is ample evidence that praecox-feeling is still relevant in modern clinical practice. This study examined the reliability of operationalized praecox-feeling against the background of modern diagnostic criteria and assessment methods.
  
  
  METHODS
  102 consecutively admitted patients (37 with a diagnosis of schizophrenia) were interviewed within 2 days of their admission to a university-affiliated acute psychiatric unit. This initial interview was observed by 5 psychiatrists who had never seen the patients before. The interview lasted 2 min and consisted of standard, non-specific questions. The observing clinicians independently rated the absence or presence of praecox-feeling for each patient at 30 s and 2 min after encountering the patients. A sixth psychiatrist then examined the patients using the SCID-DSM-IV and all available information to reach a best estimate DSM-IV diagnosis.
  
  
  RESULTS
  Measured against a research diagnosis, praecox-feeling had unsatisfactory sensitivity, specificity, positive and negative predictive values, and area under the receiver-operator curves. There was no significant difference between the 30 s and the 2 min ratings of any of the 5 clinicians. Of the socio-demographic and clinical characteristics, only early age of onset was significantly associated with praecox feeling for the majority of the raters. The raters' length of clinical experience did not correlate with the accuracy of their praecox-feeling.
  
  
  CONCLUSIONS
  Measured against a best estimate research diagnosis in this study, praecox-feeling had modest sensitivity and specificity. Diagnostic agreement with the modern gold standard diagnosis of schizophrenia for all raters of praecox-feeling was poor. Although praecox-feeling appears to be an unreliable diagnostic compass, several lines of evidence suggest that its existence in clinical practice cannot be denied, which underscores the importance of a subjective element of unknown composition, magnitude and reliability in the diagnostic process that deserves more attention.
authors.affiliation: Department of Psychiatry, Chinese University of Hong Kong, Hong Kong, SAR, China.
authors.forename: Gabor S
authors.initials: GS
authors.lastname: Ungvari
authors.forename: Yu-Tao
authors.initials: YT
authors.lastname: Xiang
authors.forename: Yu
authors.initials: Y
authors.lastname: Hong
authors.forename: Henry C M
authors.initials: HC
authors.lastname: Leung
authors.forename: Helen F K
authors.initials: HF
authors.lastname: Chiu
mesh_terms: D016009:Chi-Square Distribution; D039721:Diagnostic and Statistical Manual of Mental Disorders; D006801:Humans; D007406:Interview, Psychological; D011570:Psychiatry; D015203:Reproducibility of Results; D012559:Schizophrenia / Q000175:diagnosis*; D012680:Sensitivity and Specificity