Chinese version of MDQ effective for BD screening
MedWire News: The Chinese version of the Mood Disorder Questionnaire (MDQ-C) is an effective screening tool for bipolar disorder (BD) among patients who have experienced a major depressive episode, say researchers.
Writing in BMC Psychiatry, Jinbei Zhang (Sun Yat-sen University, Guangzhou, China) and colleagues explain that "the MDQ is a well-recognized screening tool for BD, but its Chinese version needs further validation."
The team therefore studied 122 Chinese patients with a major depressive episode who received an initial diagnosis of unipolar depression (UPD), bipolar II disorder (BD II), or bipolar I disorder (BD I), using the Structured Clinical Interview for DSM-IV-text revision Axis 1 Disorders (SCID-I), and who were followed-up for 1 year.
All of the participants completed the MDQ-C at baseline, and the final diagnosis at 1 year was made by a committee of three trained senior psychiatrists, who interviewed the participants at least six times over the study period.
Overall, 48.4% (n=59) of the participants received an initial diagnosis of UPD, 36.9% (n=45) BD II, and 14.8% (n=18) BD I.
After 1 year, nine patients initially diagnosed with UPD had switched to a diagnosis of BD II (n=8) or BD I (n=1), two had switched from BD II to UPD, and one from BD II to BD I. The overall rate of initial misdiagnosis was 16.4%.
The researchers found that the MDQ-C had good accuracy for diagnosing bipolar disorder, with receiver operating characteristic curve analysis indicating a sensitivity of 0.72 and a specificity of 0.73 at an optimal cut-off score of 4 in section one of the questionnaire.
Regarding BD subtypes, the optimal cut-off score for BD II was 4 in section one of the questionnaire, with a sensitivity of 0.70 and a specificity of 0.73, while the optimal cut-off score for BD I was 5, with a sensitivity of 0.67 and a specificity of 0.86.
The researchers note that there were significant levels of misunderstanding in sections two and three of the questionnaire, and these sections were therefore excluded from the analysis.
Zhang and team conclude: "Our study shows that the Chinese version of the MDQ without sections two and three is a valid, brief and feasible tool for screening BD from patients with a current depressive episode."
However, they add that "the small sample size in our study makes a larger prospective study necessary… under different clinical settings."
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By Mark Cowen