title: Inter-informant agreement and prevalence estimates for mood syndromes: direct interview vs. family history method.
abstract: BACKGROUND
  The use of the family history method is recommended in family studies as a type of proxy interview of non-participating relatives. However, using different sources of information can result in bias as direct interviews may provide a higher likelihood of assigning diagnoses than family history reports. The aims of the present study were to: (1) compare diagnoses for threshold and subthreshold mood syndromes from interviews to those relying on information from relatives; (2) test the appropriateness of lowering the diagnostic threshold and combining multiple reports from the family history method to obtain comparable prevalence estimates to the interviews; (3) identify factors that influence the likelihood of agreement and reporting of disorders by informants.
  
  
  METHODS
  Within a family study, 1621 informant-index subject pairs were identified. DSM-5 diagnoses from direct interviews of index subjects were compared to those derived from family history information provided by their first-degree relatives.
  
  
  RESULTS
  (1) Inter-informant agreement was acceptable for Mania, but low for all other mood syndromes. (2) Except for Mania and subthreshold depression, the family history method provided significantly lower prevalence estimates. The gap improved for all other syndromes after lowering the threshold of the family history method. (3) Individuals who had a history of depression themselves were more likely to report depression in their relatives.
  
  
  CONCLUSIONS
  Low proportion of affected individuals for manic syndromes and lack of independence of data.
  
  
  CONCLUSIONS
  The higher likelihood of reporting disorders by affected informants entails the risk of overestimation of the size of familial aggregation of depression.
authors.affiliation: Department of Psychiatry, University Hospital of Lausanne, Site de Cery, 1008 Prilly, Switzerland. Electronic address: Caroline.Vandeleur@chuv.ch.
authors.forename: C L
authors.initials: CL
authors.lastname: Vandeleur
authors.affiliation: Department of Psychiatry, University Hospital of Lausanne, Site de Cery, 1008 Prilly, Switzerland; Department of Mental Health and Psychiatry, University Hospital of Geneva, Switzerland.
authors.forename: S
authors.initials: S
authors.lastname: Rothen
authors.affiliation: Department of Psychiatry, University Hospital of Lausanne, Site de Cery, 1008 Prilly, Switzerland; Department of Mental Health and Psychiatry, University Hospital of Geneva, Switzerland.
authors.forename: Y
authors.initials: Y
authors.lastname: Lustenberger
authors.affiliation: Department of Psychiatry, University Hospital of Lausanne, Site de Cery, 1008 Prilly, Switzerland; Department of Mental Health and Psychiatry, University Hospital of Geneva, Switzerland.
authors.forename: J
authors.initials: J
authors.lastname: Glaus
authors.affiliation: Department of Psychiatry, University Hospital of Lausanne, Site de Cery, 1008 Prilly, Switzerland.
authors.forename: E
authors.initials: E
authors.lastname: Castelao
authors.affiliation: Department of Psychiatry, University Hospital of Lausanne, Site de Cery, 1008 Prilly, Switzerland.
authors.forename: M
authors.initials: M
authors.lastname: Preisig
mesh_terms: D000328:Adult; D005060:Europe / Q000453:epidemiology; D005190:Family / Q000523:psychology*; D005192:Family Health / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D007406:Interview, Psychological / Q000379:methods*; D008297:Male; D008487:Medical History Taking / Q000379:methods* / Q000706:statistics & numerical data*; D019964:Mood Disorders / Q000175:diagnosis* / Q000453:epidemiology*; D015995:Prevalence; D015203:Reproducibility of Results; D013557:Switzerland / Q000453:epidemiology; D013577:Syndrome
keywords: DSM-5; Family history method; Family study; Inter-informant agreement; Mood syndromes; Prevalence