Examination of the Chicago Multiscale Depression Inventory and Initial Validation of a Positive Scale.

The Chicago Multiscale Depression Inventory (CMDI) was developed to improve accuracy in measuring depression symptoms in individuals with non-psychiatric medical illness. Earlier psychometric evaluation of the CMDI has emphasized properties of items that measure negative affect and experience. In this study, we provide an initial evaluation of an outcome scale of positive items that are also included within the CMDI but have previously been excluded from calculation of the total score. Psychometric data for the CMDI negative and positive item subscales were determined in healthy adults and patients with multiple sclerosis. Analysis included measurements of factor structure, reliability, and validity in comparison with other established measures of depression and affect. Study findings indicate that in healthy and patient samples, the CMDI Positive scale has very good reliability and validity. The Positive scale score also appears to predict depression symptoms beyond the negative item scale scores. The CMDI Positive scale could be a valuable clinical and research tool. Inclusion of the Positive scale in the CMDI total score appears to improve the measure by further capturing symptoms of affect and experience that are important to diagnosis of depression and are not covered by the negative scales alone. (JINS, 2016, 22, 76-82).