Reliability and validity of the bipolar depression rating scale on an Iranian sample

Background: The Bipolar Depression Rating Scale is an instrument to measure depression severity in patients diagnosed with bipolar disorder. This study has reevaluated the psychometric values of the Bipolar Depression Rating Scale through assessing an Iranian sample of patients with bipolar depression. Methods: A total of 60 patients (36 males and 24 females) with bipolar depression referred to four medical centers in Tehran, Iran were interviewed with the Structured Clinical Interview for DSM-IV axis I Disorders, Young Mania Rating Scale, center for Epidemiological Studies Depression Scale, and the Bipolar Depression Rating Scale. Internal consistency and inter-rater reliability of the Bipolar Depression Rating Scale, and Pearson's correlation coefficient between the Bipolar Depression Rating Scale and Young Mania Rating Scale/Center for Epidemiological Studies Depression Scale were calculated. Results: The Cronbach's alpha coefficient was 0.81. The Pearson's correlation coefficients of the Bipolar Depression Rating Scale with the Center for Epidemiological Studies Depression Scale and Young Mania Rating Scale were 0.73 and -0.82, respectively. The correlation coeffcients between the two raters for the total score of the Bipolar Depression Rating Scale according to the Pearson's correlation and intraclass correlation tests were 0.83 and 0.89, respectively. Conclusion: The Bipolar Depression Rating Scale is a reliable and valid instrument to use in studies on Iranian clinical patients with bipolar depression