title: Hypersomnia subtypes, sleep and relapse in bipolar disorder.
abstract: BACKGROUND
  Though poorly defined, hypersomnia is associated with negative health outcomes and new-onset and recurrence of psychiatric illness. Lack of definition impedes generalizability across studies. The present research clarifies hypersomnia diagnoses in bipolar disorder by exploring possible subgroups and their relationship to prospective sleep data and relapse into mood episodes.
  
  
  METHODS
  A community sample of 159 adults (aged 18-70 years) with bipolar spectrum diagnoses, euthymic at study entry, was included. Self-report inventories and clinician-administered interviews determined features of hypersomnia. Participants completed sleep diaries and wore wrist actigraphs at home to obtain prospective sleep data. Approximately 7 months later, psychiatric status was reassessed. Factor analysis and latent profile analysis explored empirical groupings within hypersomnia diagnoses.
  
  
  RESULTS
  Factor analyses confirmed two separate subtypes of hypersomnia ('long sleep' and 'excessive sleepiness') that were uncorrelated. Latent profile analyses suggested a four-class solution, with 'long sleep' and 'excessive sleepiness' again representing two separate classes. Prospective sleep data suggested that the sleep of 'long sleepers' is characterized by a long time in bed, not long sleep duration. Longitudinal assessment suggested that 'excessive sleepiness' at baseline predicted mania/hypomania relapse.
  
  
  CONCLUSIONS
  This study is the largest of hypersomnia to include objective sleep measurement, and refines our understanding of classification, characterization and associated morbidity. Hypersomnia appears to be comprised of two separate subgroups: long sleep and excessive sleepiness. Long sleep is characterized primarily by long bedrest duration. Excessive sleepiness is not associated with longer sleep or bedrest, but predicts relapse to mania/hypomania. Understanding these entities has important research and treatment implications.
authors.affiliation: Department of Psychiatry,Stanford University School of Medicine,Stanford,CA,USA.
authors.forename: K A
authors.initials: KA
authors.lastname: Kaplan
authors.affiliation: Division of Child and Adolescent Psychiatry,Columbia University Medical Center/New York State Psychiatric Institute,New York,NY,USA.
authors.forename: E L
authors.initials: EL
authors.lastname: McGlinchey
authors.affiliation: Department of Psychiatry,University of Pittsburgh School of Medicine,Pittsburgh,PA,USA.
authors.forename: A
authors.initials: A
authors.lastname: Soehner
authors.affiliation: Department of Psychiatry,Stanford University School of Medicine,Stanford,CA,USA.
authors.forename: A
authors.initials: A
authors.lastname: Gershon
authors.affiliation: San Francisco Veterans Affairs Medical Center,San Francisco,CA,USA.
authors.forename: L S
authors.initials: LS
authors.lastname: Talbot
authors.affiliation: Cognitive Behavior Therapy and Science Center,Oakland,CA,USA.
authors.forename: P
authors.initials: P
authors.lastname: Eidelman
authors.affiliation: Department of Psychology,University of Colorado,Boulder,CO,USA.
authors.forename: J
authors.initials: J
authors.lastname: Gruber
authors.affiliation: Department of Psychology,University of California,Berkeley,CA,USA.
authors.forename: A G
authors.initials: AG
authors.lastname: Harvey
mesh_terms: D056044:Actigraphy; D000293:Adolescent; D000328:Adult; D000368:Aged; D001714:Bipolar Disorder / Q000150:complications* / Q000523:psychology*; D006970:Disorders of Excessive Somnolence / Q000150:complications* / Q000523:psychology*; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012008:Recurrence; D012890:Sleep; D055815:Young Adult
keywords: sleep