title: Factor structure and dimensionality of the two depression scales in STAR*D using level 1 datasets.
abstract: BACKGROUND
  The factor structure and dimensionality of the HAM-D(17) and the IDS-C(30) are as yet uncertain, because psychometric analyses of these scales have been performed without a clear separation between factor structure profile and dimensionality (total scores being a sufficient statistic).
  
  
  METHODS
  The first treatment step (Level 1) in the STAR*D study provided a dataset of 4041 outpatients with DSM-IV nonpsychotic major depression. The HAM-D(17) and IDS-C(30) were evaluated by principal component analysis (PCA) without rotation. Mokken analysis tested the unidimensionality of the IDS-C(6), which corresponds to the unidimensional HAM-D(6.)
  
  
  RESULTS
  For both the HAM-D(17) and IDS-C(30), PCA identified a bi-directional factor contrasting the depressive symptoms versus the neurovegetative symptoms. The HAM-D(6) and the corresponding IDS-C(6) symptoms all emerged in the depression factor. Both the HAM-D(6) and IDS-C(6) were found to be unidimensional scales, i.e., their total scores are each a sufficient statistic for the measurement of depressive states.
  
  
  CONCLUSIONS
  STAR*D used only one medication in Level 1.
  
  
  CONCLUSIONS
  The unidimensional HAM-D(6) and IDS-C(6) should be used when evaluating the pure clinical effect of antidepressive treatment, whereas the multidimensional HAM-D(17) and IDS-C(30) should be considered when selecting antidepressant treatment.
authors: Psychiatric Research Unit, Frederiksborg General Hospital, Copenhagen University, Hillerød, Denmark. Per.bech@regionh.dk
authors: P
authors: P
authors: Bech
authors: M
authors: M
authors: Fava
authors: M H
authors: MH
authors: Trivedi
authors: S R
authors: SR
authors: Wisniewski
authors: A J
authors: AJ
authors: Rush
mesh_terms: D000328:Adult; D000928:Antidepressive Agents / Q000627:therapeutic use; D003863:Depression; D003866:Depressive Disorder / Q000175:diagnosis* / Q000188:drug therapy*; D003865:Major Depressive Disorder / Q000175:diagnosis / Q000188:drug therapy; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D008297:Male; D001523:Mental Disorders / Q000188:drug therapy; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales / Q000592:standards*; D011594:Psychometrics / Q000295:instrumentation*; D014894:Weights and Measures
chemical_list: D000928:Antidepressive Agents