title: A prospective investigation of the natural history of the long-term weekly symptomatic status of bipolar II disorder.
abstract: BACKGROUND
  This is the first prospective longitudinal study, to our knowledge, of the natural history of the weekly symptomatic status of bipolar II disorder (BP-II).
  
  
  METHODS
  Weekly affective symptom status ratings for 86 patients with BP-II were based on interviews conducted at 6- or 12-month intervals during a mean of 13.4 years of prospective follow-up. Percentage of weeks at each symptom severity level and the number of shifts in symptom status and polarity were examined. Predictors of chronicity for BP-II were evaluated using new chronicity measures. Chronicity was also analyzed in relation to the percentage of follow-up weeks with different types of somatic treatment.
  
  
  RESULTS
  Patients with BP-II were symptomatic 53.9% of all follow-up weeks: depressive symptoms (50.3% of weeks) dominated the course over hypomanic (1.3% of weeks) and cycling/mixed (2.3% of weeks) symptoms. Subsyndromal, minor depressive, and hypomanic symptoms combined were 3 times more common than major depressive symptoms. Longer intake episodes, a family history of affective disorders, and poor previous social functioning predicted greater chronicity. Prescribed somatic treatment did not correlate significantly with symptom chronicity. Patients with BP-II of brief (2-6 days) vs longer (> or =7 days) hypomanias were not significantly different on any measure.
  
  
  CONCLUSIONS
  The longitudinal symptomatic course of BP-II is chronic and is dominated by depressive rather than hypomanic or cycling/mixed symptoms. Symptom severity fluctuates frequently within the same patient over time, involving primarily symptoms of minor and subsyndromal severity. Longitudinally, BP-II is expressed as a dimensional illness involving the full severity range of depressive and hypomanic symptoms. Hypomania of long or short duration in BP-II seems to be part of the same disease process.
authors.affiliation: Department of Psychiatry, University of California, San Diego, La Jolla 92093-0603, USA.
authors.forename: Lewis L
authors.initials: LL
authors.lastname: Judd
authors.forename: Hagop S
authors.initials: HS
authors.lastname: Akiskal
authors.forename: Pamela J
authors.initials: PJ
authors.lastname: Schettler
authors.forename: William
authors.initials: W
authors.lastname: Coryell
authors.forename: Jean
authors.initials: J
authors.lastname: Endicott
authors.forename: Jack D
authors.initials: JD
authors.lastname: Maser
authors.forename: David A
authors.initials: DA
authors.lastname: Solomon
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Leon
authors.forename: Martin B
authors.initials: MB
authors.lastname: Keller
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000368:Aged; D000928:Antidepressive Agents / Q000627:therapeutic use; D014150:Antipsychotic Agents / Q000627:therapeutic use; D001714:Bipolar Disorder / Q000175:diagnosis* / Q000523:psychology / Q000628:therapy; D002908:Chronic Disease; D004565:Electroconvulsive Therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D012720:Severity of Illness Index
chemical_list: D000928:Antidepressive Agents; D014150:Antipsychotic Agents