title: The prevalence of bipolar spectrum disorder in elderly patients with recurrent depression.
abstract: OBJECTIVE
  Despite a growing body of knowledge on bipolar spectrum disorder (BSD), relatively little is known about the clinical characteristics of BSD in elderly people. We investigated the prevalence of BSD in elderly patients with recurrent depression.
  
  
  METHODS
  A total of 65 elderly outpatients (≥60 years of age) who met the Diagnostic and Statistical Manual of Mental Disorders IV criteria for recurrent major depressive disorder participated in the study. BSD was diagnosed according to the criteria developed by Ghaemi et al and the Mood Disorder Questionnaire (MDQ) was used to assess bipolarity.
  
  
  RESULTS
  Of 65 subjects, eleven (16.9%) and 54 (83.1%) were diagnosed with BSD and unipolar depression, respectively. A total of 32.3% (n=22) had a positive screen for bipolar disorder, and we found a significant association between the BSD criteria and the criteria for a positive MDQ (P<0.001). Patients with BSD had a longer duration of illness (P=0.040) and more prior depressive episodes (P<0.001) than did those with unipolar depression. The BSD criteria of first-degree relative with bipolar disorder (P=0.030), antidepressant-induced hypomania (P=0.034), hyperthymic personality (P=0.001), and atypical depression (P=0.030) were highly associated with MDQ-positive patients.
  
  
  CONCLUSIONS
  Our results indicate that many depressed elderly patients have bipolar-related illness; moreover, some features of the depression are associated with bipolarity.
authors.affiliation: Department of Psychiatry, School of Medicine, Jeju National University, Jeju, Republic of Korea.
authors.forename: Chang-In
authors.initials: CI
authors.lastname: Lee
authors.affiliation: Department of Psychiatry, School of Medicine, Jeju National University, Jeju, Republic of Korea.
authors.forename: Young-Eun
authors.initials: YE
authors.lastname: Jung
authors.affiliation: Department of Psychiatry, School of Medicine, Jeju National University, Jeju, Republic of Korea.
authors.forename: Moon-Doo
authors.initials: MD
authors.lastname: Kim
authors.affiliation: Department of Preventive Medicine, School of Medicine, Jeju National University, Jeju, Republic of Korea.
authors.forename: Seong-Chul
authors.initials: SC
authors.lastname: Hong
authors.affiliation: Department of Psychiatry, Yeouido St Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Won-Myong
authors.initials: WM
authors.lastname: Bahk
authors.affiliation: Department of Psychiatry, Naju National Hospital, Naju, Republic of Korea.
authors.forename: Bo-Hyun
authors.initials: BH
authors.lastname: Yoon
keywords: MDQ; bipolarity; elderly; unipolar depression