title: Factors associated with relapse after a response to electroconvulsive therapy in unipolar versus bipolar depression.
abstract: While electroconvulsive therapy (ECT) treatment for depression is highly effective, the high rate of relapse is a critical problem. The current study investigated factors associated with the risk of relapse in mood disorders in patients in which ECT was initially effective.
  
  
  
  The records of 100 patients with mood disorders (61 unipolar depression, 39 bipolar depression) who received and responded to an acute ECT course were retrospectively reviewed. Associations between clinical variables and relapse after responding to acute ECT were analyzed. The Ethics Committee of NHO Kure Medical Center approved the study protocol.
  
  
  
  After one year, the percentage of relapse-free patients was 48.7%. There was no significant difference between patients with either unipolar or bipolar depression who were relapse-free (unipolar: 51.1%, bipolar: 45.5%, P=0.603). Valproate maintenance pharmacotherapy in unipolar depression patients was associated with a lower risk of relapse compared to patients without valproate treatment (multivariate analysis, hazard ratio: 0.091; P=0.022). Lithium treatment, reportedly effective for unipolar depression following a course of ECT, tended to lower the risk of relapse (hazard ratio: 0.378; P=0.060). For bipolar depression, no treatment significantly reduced the risk of relapse.
  
  
  
  The current findings were retrospective and based on a limited sample size.
  
  
  
  The relapse-free rate was similar between unipolar and bipolar depression. Valproate could have potential for unipolar depression patients as a maintenance therapeutic in preventing relapse after ECT.
authors.affiliation: Division of Psychiatry and Neuroscience, Institute for Clinical Research, National Hospital Organization (NHO) Kure Medical Center and Chugoku Cancer Center, 3-1, Aoyama, Kure, Hiroshima 737-0023, Japan; Department of Psychiatry, NHO Kure Medical Center and Chugoku Cancer Center, Kure, Hiroshima, Japan; Department of Psychiatry and Neurosciences, Division of Frontier Medical Science, Programs for Biomedical Research, Graduate School of Biomedical Sciences, Hiroshima University, 1-2-3, Kasumi, Minami-ku, Hiroshima 734-0037 Japan.
authors.forename: Kei
authors.initials: K
authors.lastname: Itagaki
authors.affiliation: Division of Psychiatry and Neuroscience, Institute for Clinical Research, National Hospital Organization (NHO) Kure Medical Center and Chugoku Cancer Center, 3-1, Aoyama, Kure, Hiroshima 737-0023, Japan; Department of Psychiatry, NHO Kure Medical Center and Chugoku Cancer Center, Kure, Hiroshima, Japan. Electronic address: mtakebayashi@kure-nh.go.jp.
authors.forename: Minoru
authors.initials: M
authors.lastname: Takebayashi
authors.affiliation: Division of Psychiatry and Neuroscience, Institute for Clinical Research, National Hospital Organization (NHO) Kure Medical Center and Chugoku Cancer Center, 3-1, Aoyama, Kure, Hiroshima 737-0023, Japan; Department of Psychiatry and Neurosciences, Division of Frontier Medical Science, Programs for Biomedical Research, Graduate School of Biomedical Sciences, Hiroshima University, 1-2-3, Kasumi, Minami-ku, Hiroshima 734-0037 Japan.
authors.forename: Chiyo
authors.initials: C
authors.lastname: Shibasaki
authors.affiliation: Division of Psychiatry and Neuroscience, Institute for Clinical Research, National Hospital Organization (NHO) Kure Medical Center and Chugoku Cancer Center, 3-1, Aoyama, Kure, Hiroshima 737-0023, Japan.
authors.forename: Naoto
authors.initials: N
authors.lastname: Kajitani
authors.affiliation: Division of Psychiatry and Neuroscience, Institute for Clinical Research, National Hospital Organization (NHO) Kure Medical Center and Chugoku Cancer Center, 3-1, Aoyama, Kure, Hiroshima 737-0023, Japan.
authors.forename: Hiromi
authors.initials: H
authors.lastname: Abe
authors.affiliation: Division of Psychiatry and Neuroscience, Institute for Clinical Research, National Hospital Organization (NHO) Kure Medical Center and Chugoku Cancer Center, 3-1, Aoyama, Kure, Hiroshima 737-0023, Japan.
authors.forename: Mami
authors.initials: M
authors.lastname: Okada-Tsuchioka
authors.affiliation: Department of Psychiatry and Neurosciences, Division of Frontier Medical Science, Programs for Biomedical Research, Graduate School of Biomedical Sciences, Hiroshima University, 1-2-3, Kasumi, Minami-ku, Hiroshima 734-0037 Japan. Electronic address: yamawaki@hiroshima-u.ac.jp.
authors.forename: Shigeto
authors.initials: S
authors.lastname: Yamawaki
mesh_terms: D000328:Adult; D000368:Aged; D001714:Bipolar Disorder / Q000628:therapy*; D003866:Depressive Disorder / Q000628:therapy*; D004565:Electroconvulsive Therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D012189:Retrospective Studies; D016896:Treatment Outcome