A prospective investigation of the natural history of the long-term weekly symptomatic status of bipolar II disorder.
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.
Judd
Lewis L
LL
Department of Psychiatry, University of California, San Diego, La Jolla 92093-0603, USA.
Akiskal
Hagop S
HS
Schettler
Pamela J
PJ
Coryell
William
W
Endicott
Jean
J
Maser
Jack D
JD
Solomon
David A
DA
Leon
Andrew C
AC
Keller
Martin B
MB
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
D000928:Antidepressive Agents; D014150:Antipsychotic Agents