title: Toward a generalizable model of symptoms in major depressive disorder.
abstract: BACKGROUND
  This study has two goals: 1) to establish a generalizable model of the symptoms observed in outpatients with major depressive disorder (MDD); and 2) to compare symptom coverage of the Inventory of Depressive Symptomatology, Clinician-Rated (IDS-C) and Self-Report (IDS-SR) to that of the Hamilton Depression Rating Scale (HDRS) and Beck Depression Inventory (BDI).
  
  
  METHODS
  A factor analysis of IDS-C, IDS-SR, HDRS, and BDI items was carried out on 324 adult outpatients with MDD. Patients with coexisting Axis I or III illness or those taking psychotropic medication were excluded.
  
  
  RESULTS
  Ten primary factors were identified, six of which were substantially intercorrelated, defining a second-order factor of general depression severity. Schmid-Leiman orthogonalization identified the symptoms most associated with general severity.
  
  
  CONCLUSIONS
  The IDS provided more complete factors coverage than did the HDRS or BDI and thus may be more useful in research on symptom profiles.
authors.affiliation: Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, USA.
authors.forename: C M
authors.initials: CM
authors.lastname: Gullion
authors.forename: A J
authors.initials: AJ
authors.lastname: Rush
mesh_terms: D000328:Adult; D003866:Depressive Disorder / Q000523:psychology*; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D008297:Male; D008960:Models, Psychological; D011569:Psychiatric Status Rating Scales