title: Admixture analysis of age at onset in bipolar disorder.
abstract: The aim of this study was to identify whether age at onset (AAO) identifies Bipolar Disorder (BD) subtypes, and to test whether the subgroups were confirmed by different clinical profiles. Admixture analysis was applied to determine a model that best fit the observed distribution of AAO in 964 BD patients. Three distributions of AAO were identified, and age means were 16.1 (S.D. 4.2), 25.4 (S.D. 2.5) and 32.2 (S.D. 9.5) years. A significant increased rate of suicide attempts, Bipolar I (BD I) caseness, and depressive onset was observed in the early-onset group when compared to those with later-onset by means of χ². Findings from extant studies and our results are remarkably consistent in showing that BD can be subdivided into three groups based on AAO distributions, and that early-onset is associated with higher rates of suicide attempts.
authors.affiliation: Genetics Division, GlaxoSmithKline R&D, Verona, Italy. federica.2.tozzi@gsk.com
authors.forename: Federica
authors.initials: F
authors.lastname: Tozzi
authors.forename: Mirko
authors.initials: M
authors.lastname: Manchia
authors.forename: Nicholas W
authors.initials: NW
authors.lastname: Galwey
authors.forename: Giovanni
authors.initials: G
authors.lastname: Severino
authors.forename: Maria
authors.initials: M
authors.lastname: Del Zompo
authors.forename: Richard
authors.initials: R
authors.lastname: Day
authors.forename: Keith
authors.initials: K
authors.lastname: Matthews
authors.forename: John
authors.initials: J
authors.lastname: Strauss
authors.forename: James L
authors.initials: JL
authors.lastname: Kennedy
authors.forename: Peter
authors.initials: P
authors.lastname: McGuffin
authors.forename: John B
authors.initials: JB
authors.lastname: Vincent
authors.forename: Anne
authors.initials: A
authors.lastname: Farmer
authors.forename: Pierandrea
authors.initials: P
authors.lastname: Muglia
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D001714:Bipolar Disorder / Q000453:epidemiology*; D016009:Chi-Square Distribution; D003431:Cross-Cultural Comparison; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012737:Sex Factors; D055815:Young Adult