title: Validation of the Chinese version of the "Mood Disorder Questionnaire" for screening bipolar disorder among patients with a current depressive episode.
abstract: BACKGROUND
  The Mood Disorder Questionnaire (MDQ) is a well-recognized screening tool for bipolar disorder, but its Chinese version needs further validation. This study aims to measure the accuracy of the Chinese version of the MDQ as a screening instrument for bipolar disorder (BPD) in a group of patients with a current major depressive episode.
  
  
  METHODS
  142 consecutive patients with an initial DSM-IV-TR diagnosis of a major depressive episode were screened for BPD using the Chinese translation of the MDQ and followed up for one year. The final diagnosis, determined by a special committee consisting of three trained senior psychiatrists, was used as a 'gold standard' and ROC was plotted to evaluate the performance of the MDQ. The optimal cut-off was chosen by maximizing the Younden's index.
  
  
  RESULTS
  Of the 142 patients, 122 (85.9%) finished the one year follow-up. On the basis of a semi-structured clinical interview 48.4% (59/122) received a diagnosis of unipolar depression (UPD), 36.9% (45/122) BPDII and 14.8% (18/122) BPDI. At the end of the one year follow-up,9 moved from UPD to BPD, 2 from BPDII to UPD, 1 from BPDII to BPDI, the overall rate of initial misdiagnosis was 16.4%. MDQ showed a good accuracy for BPD: the optimal cut-off was 4, with a sensitivity of 0.72 and a specificity of 0.73. When BPDII and BPDI were calculated independently, the optimal cut-off for BPDII was 4, with a sensitivity of 0.70 and a specificity of 0.73; while the optimal cut-off for BPDI was 5, with a sensitivity of 0.67 and a specificity of 0.86.
  
  
  CONCLUSIONS
  Our results show that the Chinese version of MDQ is a valid tool for screening BPD in a group of patients with current depressive episode on the Chinese mainland.
authors.affiliation: Psychiatry Department, the Third Affiliated Hospital, Sun Yat-sen University, Guangzhou 510630, China.
authors.forename: Zhaoyu
authors.initials: Z
authors.lastname: Gan
authors.forename: Zili
authors.initials: Z
authors.lastname: Han
authors.forename: Kanglai
authors.initials: K
authors.lastname: Li
authors.forename: Feici
authors.initials: F
authors.lastname: Diao
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Wu
authors.forename: Nianhong
authors.initials: N
authors.lastname: Guan
authors.forename: Jinbei
authors.initials: J
authors.lastname: Zhang
mesh_terms: D000328:Adult; D001714:Bipolar Disorder / Q000175:diagnosis*; D002681:China; D003865:Major Depressive Disorder / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods; D008875:Middle Aged; D011594:Psychometrics; D012680:Sensitivity and Specificity; D011795:Surveys and Questionnaires