Background: Depression and obesity are prevalent non-communicable conditions in the world. Validation studies of psychometric tool to detect depression are required before the application. We aimed to estimate the reliability and criterion validity of the Montgomery-Åsberg Depression Rating Scale (MADRS) and the utility of a short version proposed to bariatric surgery candidates.
Methods: Subjects were obese patients consecutively recruited from the waiting list of a bariatric surgery clinic and were assessed by trained psychologists. The sample of 374 participants was comprised of: women 80%, mean BMI 47 kg/m2, mean age 43.3 years. The psychometric performance of the MADRS was analyzed against the Structured Clinical Interview for DSM-IV Axis I Diagnosis (SCID-I). Items that showed small relevance to sample’s characteristics and contribution to data variability were sequentially removed to develop the short 5-item version of scale.
Results: For the 10-item MADRS, the Cronbach’s alpha coefficient was 0.93. When compared against SCID-I, the best cut-off threshold was 13/14, yielding sensitivity of 0.81 and specificity 0.85. The 5-item version showed an alpha coefficient of 0.94 and a best cut-off threshold of 10/11, yielding sensitivity of 0.81 and specificity 0.87. Similar overall ability to discriminate depression of almost 90% was found for 10-item and 5-item MADRS.
Limitation: Participants were recruited in a single bariatric surgery service.
Conclusion: The 10-item and 5-item MADRS are homogeneous and valid instruments to assess depressive symptoms among treatment-seeking bariatric patients. Systematic application of the short version MADRS can enhance the detection of depression during perioperative period.
Keywords: Depression, Obesity, Psychometric instrument, Bariatric surgery.