title: Development and use of a biological rhythm interview.
abstract: BACKGROUND
  As several lines of evidence point to irregular biological rhythms in bipolar disorder, and its disruption may lead to new illness episodes, having an instrument that measures biological rhythms is critical. This report describes the validation of a new instrument, the Biological Rhythms Interview of Assessment in Neuropsychiatry (BRIAN), designed to assess biological rhythms in the clinical setting.
  
  
  METHODS
  Eighty-one outpatients with a diagnosis of bipolar disorder and 79 control subjects matched for type of health service used, sex, age and educational level were consecutively recruited. After a pilot study, 18 items evaluating sleep, activities, social rhythm and eating pattern were probed for discriminant, content and construct validity, concurrent validity with the Pittsburgh Sleep Quality Index (PSQI), internal consistency and test-retest reliability.
  
  
  RESULTS
  A three-factor solution, termed sleep/social rhythm factor, activity factor and feeding factor, provided the best theoretical and most parsimonious account of the data; items essentially loaded in factors as theoretically intended, with the exception of the sleep and social scales, which formed a single factor. Test-retest reliability and internal consistency were excellent. Highly significant differences between the two groups were found for the whole scale and for each BRIAN factor. Total BRIAN scores were highly correlated with the global PSQI score.
  
  
  CONCLUSIONS
  The BRIAN scale presents a consistent profile of validity and reliability. Its use may help clinicians to better assess their patients and researchers to improve the evaluation of the impact of novel therapies targeting biological rhythm pathways.
authors.affiliation: Bipolar Disorders Program & INCT Translational Medicine, Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Larriany Maria Falsin
authors.initials: LM
authors.lastname: Giglio
authors.forename: Pedro Vieira da Silva
authors.initials: PV
authors.lastname: Magalhães
authors.forename: Ana Cristina
authors.initials: AC
authors.lastname: Andreazza
authors.forename: Julio Cesar
authors.initials: JC
authors.lastname: Walz
authors.forename: Lourenço
authors.initials: L
authors.lastname: Jakobson
authors.forename: Paola
authors.initials: P
authors.lastname: Rucci
authors.forename: Adriane Ribeiro
authors.initials: AR
authors.lastname: Rosa
authors.forename: Maria Paz
authors.initials: MP
authors.lastname: Hidalgo
authors.forename: Eduard
authors.initials: E
authors.lastname: Vieta
authors.forename: Flávio
authors.initials: F
authors.lastname: Kapczinski
mesh_terms: D000328:Adult; D001714:Bipolar Disorder / Q000175:diagnosis* / Q000523:psychology; D002940:Circadian Rhythm; D005260:Female; D006801:Humans; D007406:Interview, Psychological; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011569:Psychiatric Status Rating Scales; D012307:Risk Factors