RESUMEN
BACKGROUND: The Mood Disorder Questionnaire (MDQ) is a screening instrument for bipolar spectrum disorders already validated in many languages. METHODS: Patients from 2 psychiatric outpatient facilities were diagnosed with bipolar disorder (BD) type I and II and major depression according to the mood module of the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (SCID), Axis I Disorders--Clinician Version. In addition, a control group of healthy subjects was selected. The diagnostic interviews were used as the gold standard against which to investigate the performance of the MDQ. The MDQ was administered to 153 subjects, distributed among 4 groups. We analyzed the test reliability and discriminative capacity of the MDQ for the detection of patients with BD. RESULTS: Based on the SCID, Axis I Disorders--Clinician Version, 52 subjects (33.3%) presented a bipolar spectrum disorder (type I, II, or not otherwise specified), 48 (32.4%) were diagnosed as having unipolar depressive disorder, whereas 54 (35.3%) were unaffected by any type of psychiatric disorder (had no psychiatric disorder according to SCID results). The sensitivity for bipolar disorder was 0.72 (bipolar I disorder, 0.81; bipolar II disorder, 0.58; and bipolar disorder not otherwise specified, 0.69), with specificity of 0.95. The Brazilian Portuguese MDQ demonstrated adequate internal consistency (Cronbach α = .87). LIMITATIONS: Recruiting patients attending tertiary services may inflate the performance of the MDQ. CONCLUSIONS: The performance of the Brazilian Portuguese MDQ is comparable with other language validations. In a psychiatric outpatient sample, the Brazilian Portuguese MDQ proves to be a feasible and reliable screening instrument.