Validity of Persian Version of Mood Disorder Questionnaire in Diagnosis of Bipolar Mood Disorder in Depressive Phase

Objective: The Mood disorder questionnaire (MDQ) has been designed as a screening self-report inventory for diagnosing bipolar mood disorders. This study investigated the validity and the optimal cut-off threshold of the Persian version of MDQ in a group of Iranian depressive patients. Methods: One hundred and twenty patients with probable diagnosis of mood disorders attending psychiatric clinics were recruited to this cross-sectional study. The structured clinical interview for DSM-ΙV (SCID) was employed as the gold standard of diagnosis to discriminate between unipolar and bipolar depressions. Translated version of MDQ in Persian was completed by the patients and the final scores were summed up by a physician. The sensitivity and specificity of MDQ were calculated and compared with the diagnosis made by SCID. The ROC curve was used to determine the optimal cut-off point for diagnostic accuracy. Results: Ninety patients with bipolar depression and 30 patients with unipolar depressive disorder completed the MDQ. Internal reliability of MDQ was good with a Cronbach s alpha coefficient of 0.773. Regarding the original scoring criteria (symptoms and supplementary questions), the sensitivity and specificity of MDQ for bipolar disorder were 70% and 100% respectively. In current study, the optimal cut-off score without applying the supplementary questions was calculated to be 6 or more, with a sensitivity of 80% and a specificity of 93.3%. Conclusion: MDQ appears to be a useful screening tool for bipolar depression in Iranian psychiatric practice. Conflict of Interest: This paper is not related to financial profits of the authors and was supported by Tabriz University of Medical Sciences.