Adaptation and validation of the Melbourne Decision Making Questionnaire to Brazilian Portuguese

Introduction: Decision making (DM) is among the most important abilities for everyday functioning. However, the most widely used measures of DM come from behavioral paradigms, whose ecological validity and standalone use has been criticized in the literature. Though these issues could be addressed by the use of DM questionnaires as a complementary assessment method, no such instruments have been validated for use in Brazilian Portuguese. Therefore, the aim of this study was to conduct the translation and validation of the Melbourne Decision Making Questionnaire (MDMQ) for use in a Brazilian population. Methods: The adaptation of the MDMQ involved the following steps: translation, back-translation, expert review and pilot study. These steps were followed by factor analysis and internal consistency measurements, which led to the exclusion of 4 items from the scale. The 18-item version of the MDMQ was then administered to a validation sample consisting of healthy adults, as well as patients with bipolar disorder (BD) and major depressive disorder (MDD). Results: The instrument displayed good internal consistency, with the hypervigilance subscale showing the lowest, though still acceptable, Cronbach's alpha value. Its factor structure was comparable to that of the original MDMQ according to confirmatory factor analysis. Nevertheless, the MDMQ was sensitive to both depression severity and the presence of MDD and BD, both of which are known to have an impact on DM ability. Conclusion: The version of the MDMQ produced in the present study may be an important addition to neuropsychological assessment batteries with a focus on DM and related abilities