title: Phenomenology associated with age at onset in patients with bipolar disorder at their first psychiatric hospitalization.
abstract: OBJECTIVE
  To compare the clinical presentation of patients with early-onset (age <18 years) and typical-onset (age 20-30 years) bipolar disorder at the time of first hospitalization.
  
  
  METHODS
  Patients, aged 12-45 years at their first psychiatric hospitalization, with a DSM-IV diagnosis of bipolar disorder, manic or mixed, were evaluated on measures of manic, depressive, and positive psychotic symptoms. Differences in symptom profiles between early- and typical-onset groups were examined.
  
  
  RESULTS
  One hundred three early-onset and 58 typical-onset patients were compared. Mixed episodes were more common in the early-onset group, while psychotic features and current substance use were more common in the typical-onset group. There was no significant difference in manic symptom severity ratings between early- and typical-onset groups (F = 1.8, df = 11, 144, p = 0.06). However, these groups differed in depressive (F = 4.2, df = 16, 139, p < 0.001) and positive psychotic (F = 2.8, df = 16, 139, p = 0.001) symptom profiles. Typical-onset bipolar patients reported more severe weight loss and formal thought disorder compared with early-onset patients.
  
  
  CONCLUSIONS
  Depressive and positive psychotic symptoms may differ in association with age at onset among patients with bipolar disorder. Additional studies are necessary to determine whether homogeneous phenotypes of bipolar disorder can be delineated based upon age at onset.
authors.affiliation: College of Pharmacy, University of Cincinnati, Cincinnati, OH 45267-0004, USA. nick.patel@uc.edu
authors.forename: Nick C
authors.initials: NC
authors.lastname: Patel
authors.forename: Melissa P
authors.initials: MP
authors.lastname: Delbello
authors.forename: Paul E
authors.initials: PE
authors.lastname: Keck
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Strakowski
mesh_terms: D000293:Adolescent; D000328:Adult; D000339:Affect; D000367:Age Factors; D001714:Bipolar Disorder / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010343:Patient Admission / Q000706:statistics & numerical data*; D011569:Psychiatric Status Rating Scales; D011618:Psychotic Disorders / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology; D013850:Thinking; D015431:Weight Loss