title: Psychomotor agitation in major depressive disorder is a predictive factor of mood-switching.
abstract: BACKGROUND
  The relationship between psychomotor agitation in unipolar depression and mood-switching from depression to manic, hypomanic and mixed states has been controversial. We investigated the future risk of initial mood-switching as a function of psychomotor agitation in unipolar depression.
  
  
  METHODS
  We identified 189 participants diagnosed with major depressive disorder (MDD). We divided all patients with MDD into two categories (1) agitated patients (n=74), and (2) non-agitated patients (n=115). These groups were prospectively followed and compared by time to mood-switching. Kaplan-Meier survival curves, log-rank test for trend for survivor functions, and Cox proportional hazard ratio estimates for a multivariate model were conducted to examine the risk of mood-switching by psychomotor agitation.
  
  
  RESULTS
  During follow-up, mood-switching occurred in 20.3% of the agitated patients and 7.0% of the non-agitated patients. In the Kaplan-Meier survival estimates for time to incidence of mood-switching with agitated or non-agitated patients, the cumulative probability of developing mood-switching for agitated patients was higher than those for non-agitated patients (log-rank test: χ(2)=7.148, df=1, p=0.008). Survival analysis was also performed using Cox proportional hazards regression within a multivariate model. The agitation remained significantly associated with incidence of mood-switching (HR=2.98, 95% CI: 1.18-7.51).
  
  
  CONCLUSIONS
  We did not make a clear distinction between antidepressant-induced mood-switching and spontaneous switching.
  
  
  CONCLUSIONS
  The main finding demonstrated that MDD patients with agitation were nearly threefold as likely to experience mood-switching, suggesting that psychomotor agitation in MDD may be related to an indicator of bipolarity.
authors.affiliation: Department of Psychiatry, Juntendo University, School of Medicine, Tokyo, Japan.
authors.forename: Takao
authors.initials: T
authors.lastname: Iwanami
authors.affiliation: Juntendo University Mood Disorder Project (JUMP), Department of Psychiatry, Juntendo Koshigaya Hospital, 560 Fukuroyama, Koshigaya-shi, Saitama 343-0032, Japan; Department of Psychiatry, Juntendo University, School of Medicine, Tokyo, Japan. Electronic address: hitoshim@juntendo.ac.jp.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Maeshima
authors.affiliation: Juntendo University Mood Disorder Project (JUMP), Department of Psychiatry, Juntendo Koshigaya Hospital, 560 Fukuroyama, Koshigaya-shi, Saitama 343-0032, Japan; Department of Psychiatry, Juntendo University, School of Medicine, Tokyo, Japan.
authors.forename: Hajime
authors.initials: H
authors.lastname: Baba
authors.affiliation: Department of Psychiatry, Juntendo University, School of Medicine, Tokyo, Japan.
authors.forename: Emi
authors.initials: E
authors.lastname: Satomura
authors.affiliation: Department of Psychiatry, Juntendo University, School of Medicine, Tokyo, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Namekawa
authors.affiliation: Juntendo University Mood Disorder Project (JUMP), Department of Psychiatry, Juntendo Koshigaya Hospital, 560 Fukuroyama, Koshigaya-shi, Saitama 343-0032, Japan; Department of Psychiatry, Juntendo University, School of Medicine, Tokyo, Japan.
authors.forename: Takahisa
authors.initials: T
authors.lastname: Shimano
authors.affiliation: Juntendo University Mood Disorder Project (JUMP), Department of Psychiatry, Juntendo Koshigaya Hospital, 560 Fukuroyama, Koshigaya-shi, Saitama 343-0032, Japan; Department of Psychiatry, Juntendo University, School of Medicine, Tokyo, Japan.
authors.forename: Toshihito
authors.initials: T
authors.lastname: Suzuki
authors.affiliation: Department of Psychiatry, Juntendo University, School of Medicine, Tokyo, Japan.
authors.forename: Heii
authors.initials: H
authors.lastname: Arai
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000928:Antidepressive Agents / Q000009:adverse effects / Q000627:therapeutic use; D001714:Bipolar Disorder / Q000150:complications* / Q000523:psychology*; D003865:Major Depressive Disorder / Q000150:complications* / Q000523:psychology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D019964:Mood Disorders / Q000150:complications* / Q000523:psychology*; D011237:Predictive Value of Tests; D011595:Psychomotor Agitation / Q000150:complications* / Q000523:psychology*; D016019:Survival Analysis; D055815:Young Adult
chemical_list: D000928:Antidepressive Agents
keywords: Bipolar disorder; Bipolarity; Major depressive disorder; Mood-switching; Psychomotor agitation