title: Rating scales in general practice depression: psychometric analyses of the clinical interview for depression and the Hamilton rating scale.
abstract: BACKGROUND
  Our objective was to investigate to what extent the Clinical Interview for Depression (CID) used in the general practice setting covers clinically valid subscales (depression, anxiety, and apathy) which can measure outcome of antidepressant therapy as well as identifying subsyndromes within major depressive disorder. The CID was compared to the Hamilton Depression Rating Scale (HAM-D17).
  
  
  METHODS
  146 patients from a previous study in general practice with the CID were investigated. The item response theory model established by Rasch was used to investigate the scalability (a scale׳s psychometric adequacy) of the subscales, and principal component analysis was used to identify subsyndromes with the symptoms of major depression according to DSM-5 or ICD-10.
  
  
  RESULTS
  Whereas the HAM-D17 was found not to have an acceptable scalability, the three brief CID subscales for depression (six items), anxiety (five items), and apathy (five items) all had an acceptable scalability. Within the major depressive symptoms, principal component analysis identified the CID items of hypersomnia, increased appetite or weight gain as defining the subsyndrome of atypical depression. In total 29 patients (approximately 20%) had an atypical depression.
  
  
  CONCLUSIONS
  The samples were derived from a single study and were all rated by a single rater.
  
  
  CONCLUSIONS
  The CID contains subscales of depression, anxiety, and apathy with an acceptable scalability for use in general practice. A subsyndrome of atypical depression is also a useful identifier in the treatment of depressed patients in general practice.
authors.affiliation: Psychiatric Research Unit, Psychiatric Centre North Zealand, University of Copenhagen, Dyrehavevej 48, DK-3400 Hillerød, Denmark. Electronic address: per.bech@regionh.dk.
authors.forename: Per
authors.initials: P
authors.lastname: Bech
authors.affiliation: University of Cambridge, UK.
authors.forename: Eugene
authors.initials: E
authors.lastname: Paykel
authors.affiliation: Private practice, London, UK.
authors.forename: Lester
authors.initials: L
authors.lastname: Sireling
authors.affiliation: King׳s College London, UK.
authors.forename: Jenny
authors.initials: J
authors.lastname: Yiend
mesh_terms: D000328:Adult; D003865:Major Depressive Disorder / Q000175:diagnosis* / Q000188:drug therapy / Q000523:psychology*; D005260:Female; D058006:General Practice / Q000379:methods*; D006801:Humans; D007406:Interview, Psychological / Q000379:methods*; D008297:Male; D025341:Principal Component Analysis; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data*; D011594:Psychometrics / Q000379:methods*; D016896:Treatment Outcome
keywords: Atypical depression; Clinical Interview for Depression; General practice; Hamilton Depression Rating Scale