title: Age at onset in 3014 Sardinian bipolar and major depressive disorder patients.
abstract: OBJECTIVE
  To test if onset age in major affective illnesses is younger in bipolar disorder (BPD) than unipolar-major depressive disorder (UP-MDD), and is a useful measure.
  
  
  METHODS
  We evaluated onset-age for DSM-IV-TR major illnesses in 3014 adults (18.5% BP-I, 12.5% BP-II, 69.0% UP-MDD; 64% women) at a mood-disorders center.
  
  
  RESULTS
  Median and interquartile range (IQR) onset-age ranked: BP-I = 24 (19-32) < BP-II = 29 (20-40) < UP-MDD = 32 (23-47) years (P < 0.0001), and has remained stable since the 1970s. In BP-I patients, onset was latest for hypomania, and depression presented earlier than in BP-II or UP-MDD cases. Factors associated with younger onset included: i) being unmarried, ii) more education, iii) BPD-diagnosis, iv) family-history, v) being employed, vi) ever-suicidal, vii) substance-abuse and viii) ever-hospitalized. Onset-age distinguished BP-I from UP-MDD depressive onsets with weak sensitivity and specificity.
  
  
  CONCLUSIONS
  Onset age was younger among BPD than MDD patients, and very early onset may distinguish BPD vs. UP-MDD with depressive-onset.
authors.affiliation: Department of Psychiatry, Harvard Medical School and International Consortium for Psychotic and Mood Disorders Research, McLean Division of Massachusetts General Hospital, Boston, MA, USA.
authors.forename: L
authors.initials: L
authors.lastname: Tondo
authors.forename: B
authors.initials: B
authors.lastname: Lepri
authors.forename: N
authors.initials: N
authors.lastname: Cruz
authors.forename: R J
authors.initials: RJ
authors.lastname: Baldessarini
mesh_terms: D000328:Adult; D017668:Age of Onset; D000928:Antidepressive Agents / Q000627:therapeutic use; D001714:Bipolar Disorder / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology / Q000628:therapy; D015331:Cohort Studies; D003865:Major Depressive Disorder / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology / Q000628:therapy; D039721:Diagnostic and Statistical Manual of Mental Disorders; D006760:Hospitalization; D006801:Humans; D007406:Interview, Psychological; D007558:Italy; D011613:Psychotherapy; D012008:Recurrence; D012307:Risk Factors; D012959:Socioeconomic Factors; D013406:Suicide, Attempted / Q000523:psychology
chemical_list: D000928:Antidepressive Agents