Validação da "escala diagnóstica espectro bipolar", do "questionário transtornos do humor" e sua utilização para o rastreio de pacientes com transtorno bipolar em unidades de atenção básica

Abstract

This study was conducted in two different step he first one consisted on the development and validation of Brazilian Portuguese version of two screening instruments (the Mood Disorder Questionnaire-MDQ and the Bipolar Spectrum Diagnostic Scale-BSDS) for bipolar spectrum disorders in an adult outpatient psychiatric population. Two recent studies conducted in the US and in France found an unexpectedly high prevalence of a positive screen for bipolar disorder (BD) in primary care (PC). There are few studies of the prevalence of BD in PC and there is no information about the epidemiology of BD in Brazilian PC services. The MDQ was used to investigate the prevalence of a positive screen for bipolar disorder (BD) in patients attending one of three Brazilian primary care (PC) centers. The impact of a positive screen for BD on variables such as depressive symptoms, quality of life, medical comorbities, functioning and PC service utilization was determined. Methods. Phase one - 114 consecutive patients attending an outpatient psychiatric clinic completed the MDQ and 120 patients completed the BSDS. A research psychiatrist, blind to MDQ and BSDS results, interviewed patients by means of the mood module of the Structured Clinical Interview for DSM-IV (‘gold standard’). Phase two - This cross-sectional survey recruited a systematic sample of 720 patients between 18 and 70 years of age who were seeking PC treatment. Study measures included the Mood Disorder Questionnaire, the Center for Epidemiologic Studies Depression Scale, the World Health Organization Quality of Life Instrument (abbreviated version), the Functional Comorbidity Index, the Functioning Assessment Short Test, data on past mental health care, service utilization and a review of medical records for coded diagnosis. Results. Phase one: A B-MDQ 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). A B-BSDS screening score of 16 or more items yielded: sensitivity of 0.79 (95% CI; 0.72-0.85), specificity of 0.77 (95% CI; 0.70-0.83), a positive predictive value of 0.85 (95% CI; 0.78-0.91) and a negative predictive value of 0.70 (95% CI; 0.63-0.75). Phase two. The prevalence for having positive screen for BD was 7.6% (n=55; 95% CI: 5.6-9.5%), but only 2 patients (3.6%) were recognized as having the disorder by general practitioners. A positive screen for BD was associated with significant depressive symptoms (CES-D score ≥ 16; 70.9%), with more general medical conditions and a higher primary care utilization. Patients who screened positively for BD reported worse health-related quality of life as well as impaired functioning, compared to those who screened negatively. Limitations. The psychometric properties of the MDQ for the screening of BDs in primary care are yet to be determined. Co-morbid mental disorders were not assessed. The cross-sectional design does not allow cause-effect inferences. Conclusions. B-MDQ and B-BSDS are valid instruments for the screening of bipolar disorders. The prevalence of a positive screening for BD is high, clinically significant and underrecognized in Brazilian PC settings.