title: Bipolar disorder subtypes in children and adolescents: demographic and clinical characteristics from an Australian sample.
abstract: BACKGROUND
  Bipolar disorder (BD) phenomenology in children and adolescents remains contentious. The study investigated Australian children and adolescents with bipolar I disorder (BD-I), bipolar II disorder (BD-II), or BD not otherwise specified (BD-NOS).
  
  
  METHODS
  Index episode demographics, symptomatology, functioning and diagnostic data were compared for 88 participants (63 female) aged 8-18 years (M=14.8, SD=2.5) meeting DSM-IV-TR criteria for BD-I (n=24), BD-II (n=13) or BD-NOS (n=51).
  
  
  RESULTS
  BD-I had higher rates of previous episodes, psychotropic medication (compared to BD-II but not BD-NOS), rates of inpatient admissions (compared to BD-NOS), and number of inpatient admissions (compared to BD-II). BD-II had lower rates of lifetime depression and anxiety disorders, higher frequency of hypomania, shorter duration of illness, and fewer previous episodes. BD-NOS had younger age of onset, chronic course, irritability and mixed presentation. All BD subtypes had high rates of self-harm (69.3%), suicidal ideation (73.9%), suicide attempts (36.4%), psychiatric admission (55.7%), and psychosis (36.4%).
  
  
  CONCLUSIONS
  There were relatively small numbers of BD-I and BD-II. Diagnoses were based on retrospective recall.
  
  
  CONCLUSIONS
  All BD subtypes had high levels of acuity and clinical risk. In accord with previous results, BD-I and BD-II participants' phenomenology was consistent with classical descriptions of these subtypes. BD-NOS participants were younger, with less euphoric mania but otherwise phenomenologically on a continuum with BD-I, suggesting that child and adolescent BD-NOS may be an early and less differentiated phase of illness of BD-I or BD-II and hence a target for early intervention.
authors.affiliation: Hunter New England Local Health District, Child and Adolescent Mental Health Service, Newcastle, NSW, Australia; University of Sydney, Sydney Medical School, Discipline of Psychiatry, Sydney, NSW, Australia. Electronic address: Stephen.Hirneth@hnehealth.nsw.gov.au.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Hirneth
authors.affiliation: University of Sydney, Sydney Medical School, Discipline of Psychiatry, Sydney, NSW, Australia; Sydney and South Western Sydney Local Health Districts, Infant Child and Adolescent Mental Health Services, Sydney, NSW, Australia.
authors.forename: Philip L
authors.initials: PL
authors.lastname: Hazell
authors.affiliation: School of Psychology, University of Newcastle, Callaghan, NSW, Australia.
authors.forename: Tanya L
authors.initials: TL
authors.lastname: Hanstock
authors.affiliation: University of Newcastle and Hunter New England Mental Health Services, Centre for Translational Neuroscience and Mental Health, Newcastle, NSW, Australia.
authors.forename: Terry J
authors.initials: TJ
authors.lastname: Lewin
mesh_terms: D000293:Adolescent; D000367:Age Factors; D017668:Age of Onset; D001008:Anxiety Disorders / Q000453:epidemiology / Q000523:psychology; D001315:Australia / Q000453:epidemiology; D001714:Bipolar Disorder / Q000175:diagnosis / Q000453:epidemiology* / Q000523:psychology*; D002648:Child; D003527:Cyclothymic Disorder / Q000453:epidemiology / Q000523:psychology; D003863:Depression / Q000453:epidemiology / Q000523:psychology; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D011618:Psychotic Disorders / Q000453:epidemiology* / Q000523:psychology; D012189:Retrospective Studies; D016728:Self-Injurious Behavior / Q000453:epidemiology* / Q000523:psychology; D059020:Suicidal Ideation; D013406:Suicide, Attempted / Q000523:psychology / Q000706:statistics & numerical data*
keywords: Adolescents; Bipolar disorder; Children; Phenomenology; Subtypes