title: Early-onset and very-early-onset bipolar disorder: distinct or similar clinical conditions?
abstract: OBJECTIVE
  This study aimed to examine differences in the clinical presentation of very-early-onset (VEO) and early-onset (EO) bipolar disorder (BD) not fully explored previously.
  
  
  METHODS
  We selected two groups of subjects with BD from the Maritime Bipolar Registry based on age at onset of first major mood episode (VEO with onset prior to age 15 years; EO ranging from 15 to 18 years) and compared them with a reference group (onset after 18 years of age). There were 363 subjects (240 with bipolar I disorder and 123 with bipolar II disorder; mean age 44.2 ± 12.8 (SD) years), with 41 subjects in the VEO and 95 in the EO groups.
  
  
  RESULTS
  In comparison with the EO and reference groups, more subjects in the VEO group developed major depression as an index episode (88% for the VEO group versus 61% for the EO group and 54% for the reference group), and had an unremitting clinical course (65% versus 42% and 42%, respectively), rapid cycling (54% versus 34% and 28%, respectively), and comorbid attention-deficit hyperactivity disorder (17% versus 1% and 3%, respectively); a higher proportion of the VEO group had first-degree relatives with affective disorders compared with the EO and reference groups (0.41 versus 0.32 and 0.29, respectively), and they had lower scores on the Global Assessment of Functioning scale (mean scores of 64 versus 70 and 70). Overall, the EO group was similar to the reference group on most measures, except for increased suicidal behavior VEO 53%, EO 44% and reference group 25%). The results of polychotomous logistic regression also support the view that VEO BD represents a rather specific subtype of BD.
  
  
  CONCLUSIONS
  Our results suggest the recognized correlates of early-onset BD may be driven by subjects at the lowest end of the age at onset spectrum.
authors.affiliation: Department of Psychiatry, Dalhousie University, Halifax, NS, Canada.
authors.forename: Lukas
authors.initials: L
authors.lastname: Propper
authors.affiliation: Department of Psychiatry, Dalhousie University, Halifax, NS, Canada.
authors.forename: Abigail
authors.initials: A
authors.lastname: Ortiz
authors.affiliation: Capital Health Addictions and Mental Health Program, Halifax, NS, Canada.
authors.forename: Claire
authors.initials: C
authors.lastname: Slaney
authors.affiliation: Capital Health Addictions and Mental Health Program, Halifax, NS, Canada.
authors.forename: Julie
authors.initials: J
authors.lastname: Garnham
authors.affiliation: Department of Psychiatry, Queens University, Kingston, ON, Canada.
authors.forename: Martina
authors.initials: M
authors.lastname: Ruzickova
authors.affiliation: Department of Psychiatry, Dalhousie University, Halifax, NS, Canada.
authors.forename: Cynthia V
authors.initials: CV
authors.lastname: Calkin
authors.affiliation: Department of Psychiatry, Dalhousie University, Halifax, NS, Canada.
authors.forename: Claire
authors.initials: C
authors.lastname: O'Donovan
authors.affiliation: Department of Psychiatry, Dalhousie University, Halifax, NS, Canada.|National Institute of Mental Health, Klecany, Czech Republic.
authors.forename: Tomas
authors.initials: T
authors.lastname: Hajek
authors.affiliation: Department of Psychiatry, Dalhousie University, Halifax, NS, Canada.|National Institute of Mental Health, Klecany, Czech Republic.
authors.forename: Martin
authors.initials: M
authors.lastname: Alda
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology; D001714:Bipolar Disorder / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology; D002170:Canada / Q000453:epidemiology; D015897:Comorbidity; D003865:Major Depressive Disorder / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology; D005190:Family / Q000523:psychology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019964:Mood Disorders / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology; D011569:Psychiatric Status Rating Scales; D011599:Psychopathology
keywords: bipolar disorder; childhood ADHD; early course; early onset; first mood episode; rapid cycling