title: Subtyping depression by clinical features: the Australasian database.
abstract: OBJECTIVE
  To distinguish psychotic, melancholic and a residual non-melancholic class on the basis of clinical features alone. Previous studies at our Mood Disorders Unit (MDU) favour a hierarchical model, with the classes able to be distinguished by two specific clinical features, but any such intramural study risks rater bias and requires external replication.
  
  
  METHODS
  This replication study involved 27 Australasian psychiatrist raters, thus extending the sample and raters beyond the MDU facility. They collected clinical feature data using a standardized assessment with precoded rating options. A psychotic depression (PD) class was derived by respecting DSM-IV decision rules while a cluster analysis distinguished melancholic (MEL) and non-melancholic classes.
  
  
  RESULTS
  The MELs were distinguished virtually entirely by the presence of significant psychomotor disturbance (PMD), as rated by the observationally based CORE measure, with over-representation on only three of an extensive set of 'endogeneity symptoms'.
  
  
  CONCLUSIONS
  In comparison to PMD, endogeneity symptoms appear to be poor indicators of 'melancholic' type, confounding typology with severity. Results again support the hierarchical model.
authors.affiliation: School of Psychiatry, University of New South Wales, Kensington, Australia.
authors.forename: G
authors.initials: G
authors.lastname: Parker
authors.forename: K
authors.initials: K
authors.lastname: Roy
authors.forename: D
authors.initials: D
authors.lastname: Hadzi-Pavlovic
authors.forename: P
authors.initials: P
authors.lastname: Mitchell
authors.forename: K
authors.initials: K
authors.lastname: Wilhelm
authors.forename: D B
authors.initials: DB
authors.lastname: Menkes
authors.forename: J
authors.initials: J
authors.lastname: Snowdon
authors.forename: C
authors.initials: C
authors.lastname: Loo
authors.forename: I
authors.initials: I
authors.lastname: Schweitzer
mesh_terms: D000328:Adult; D001315:Australia; D016000:Cluster Analysis; D019992:Databases as Topic; D003663:Decision Trees; D003866:Depressive Disorder / Q000145:classification* / Q000175:diagnosis* / Q000523:psychology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008960:Models, Psychological; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data*; D012720:Severity of Illness Index