Development,validity and reliability of bipolar depression index scale (BDIS)

Abstract

Objective To develop the bipolar depression index scale (BDIS) and test the validity and reliability of BDIS.Methods The original bipolar depression index scale (BDIS) was developed by the clinical features of bipolar depression reported by the studies focused on comparing the bipolar depression (BP) and unipolar depressive disorder (UP).46 patients with bipolar depression and 44 patients with unipolar depression were rated the original BDIS and enrolled consecutively by DSM-IV.Results There were eleven items in the BDIS.The interrater reliability between eleven items and BDIS score ranged from 0.61 to 0.87.The correlation coefficients between eleven items and BDIS score ranged from 0.53 to 0.73.The Cronbach's alpha of BDIS was 0.68.The mean BDIS score of BP(7.26 ± 3.12 ) was significantly higher than that of UP( (4.80 ± 3.08 ), (P ＜ 0.01 ).The BDIS scores were significantly correlated with the scores of Mood Disorder Questionnaire ( coefficient 0.56) and 32-item hypomania checklist ( coefficient 0.45).The BDIS score could discriminate between BP patients and UP patients by the ROG curve analysis and 5 was the best cutoff score ( sensitivity 0.80, specificity 0.64).Conclusions The validity and reliability of BDIS are fit for the requirements of psychometrics.BDIS may use to differentiate between bipolar depression and unipolar depression in the practice. Key words: Bipolar depression ; Unipolar depressive ; Scale ; Validity ; Reliability ;