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.