Validity of the mood disorder questionnaire in a Brazilian psychiatric population

Abstract

Objective: Bipolar spectrum disorders are prevalent and frequently underdiagnosed and undertreated. This report describes the development and validation of the Brazilian version of the Mood Disorder Questionnaire, a screening instrument for bipolar spectrum disorders, in an adult psychiatric population. Method: A total of 114 consecutive patients attending an outpatient psychiatric clinic completed the Brazilian version of the Mood Disorder Questionnaire. A research psychiatrist, blind to the Mood Disorder Questionnaire results, interviewed patients by means of the mood module of the Structured Clinical Interview for DSM-IV ('gold standard'). Results: The internal consistency of the Brazilian Mood Disorder Questionnaire, evaluated with Cronbach's alpha coefficient was 0.76 (95% CI; 0.69-0.92). Principal component analysis with varimax rotation indicated an 'irritability-racing thoughts' factor and 'energized-activity' factor, which explained 39.1% of variance. On the basis of the SCID, 69 (60.5%) individuals received a diagnosis of bipolar disorders. A Brazilian Mood Disorder Questionnaire screening score of 8 or more items yielded sensitivity of 0.91 (95% CI; 0.85-0.98), specificity of 0.70 (95% CI; 0.62-0.75), a positive predictive value of 0.82 (95% CI; 0.75-0.88) and a negative predictive value of 0.84 (95% CI; 0.77-0.90). Conclusion: The present data demonstrate that the Brazilian Mood Disorder Questionnaire is a valid instrument for the screening of bipolar disorders. The instrument needs to be validated in other settings (e.g., in general practice).