title: Self-reported data from patients with bipolar disorder: impact on minimum episode length for hypomania.
abstract: OBJECTIVE
  Some investigators have suggested decreasing the minimum hypomania episode length criterion from 4 days, as in the DSM-IV, to 2 days. Using daily self-reported mood ratings, we studied the impact of changing the length requirement on the number of hypomanic episodes in patients with bipolar disorder.
  
  
  METHODS
  203 patients (135 bipolar I and 68 bipolar II by DSM-IV criteria) recorded mood daily using ChronoRecord software (30,348 total days, mean 150 days). Episodes of hypomania and days of hypomania outside of episodes were determined.
  
  
  RESULTS
  Decreasing the minimum duration criterion for an episode of hypomania from 4 to 2 days doubled the mean percent of days in a hypomanic episode for each patient (4% to 8%), doubled the number of patients with a hypomanic episode (44 to 96) and increased the number of hypomanic episodes for all patients about three-fold (129 to 404). With a minimum episode length of 4 days, bipolar I patients were more likely to report hypomania outside episodes than bipolar II patients (p=0.010), but with a length of 2 or 3 days there was no significant difference in the distribution of hypomania outside of episodes by diagnosis. With a 2-day length, about one-third (36%) of hypomania remained outside of an episode.
  
  
  CONCLUSIONS
  Self-reported data, computer access, relatively short length, fewer bipolar II than bipolar I patients.
  
  
  CONCLUSIONS
  As the minimum length for an episode of hypomania decreases, there was a large increase in both the number of episodes and number of patients with episodes. One-day hypomania outside of episodes occurs frequently in both bipolar I and bipolar II disorder.
authors.affiliation: Department of Psychiatry and Psychotherapy, Charité University Medicine Berlin, Campus Charité-Mitte (CCM), Schumannstr. 20/21, 10117 Berlin, Germany. michael.bauer@charite.de
authors.forename: Michael
authors.initials: M
authors.lastname: Bauer
authors.forename: Paul
authors.initials: P
authors.lastname: Grof
authors.forename: Natalie L
authors.initials: NL
authors.lastname: Rasgon
authors.forename: Wendy
authors.initials: W
authors.lastname: Marsh
authors.forename: Rodrigo A
authors.initials: RA
authors.lastname: Munoz
authors.forename: Kemal
authors.initials: K
authors.lastname: Sagduyu
authors.forename: Martin
authors.initials: M
authors.lastname: Alda
authors.forename: Danilo
authors.initials: D
authors.lastname: Quiroz
authors.forename: Tasha
authors.initials: T
authors.lastname: Glenn
authors.forename: Christopher
authors.initials: C
authors.lastname: Baethge
authors.forename: Peter C
authors.initials: PC
authors.lastname: Whybrow
mesh_terms: D000328:Adult; D000339:Affect; D001714:Bipolar Disorder / Q000145:classification / Q000175:diagnosis* / Q000453:epidemiology / Q000523:psychology; D003430:Cross-Sectional Studies; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D006801:Humans; D008297:Male; D008499:Medical Records; D008875:Middle Aged; D012647:Self-Assessment