Psychometric properties and validity of Beck Depression Inventory II in multiple sclerosis

Background and purpose: Depression is the most common psychiatric disorder in multiple sclerosis (MS). Self-report depression scales are frequently used as screening, diagnostic and grading instruments. This study investigated the psychometric properties of the Beck Depression Inventory second edition (BDI-II) for assessing depressive disorders in a sample of Italian MS patients.

Methods: The sample included 141 consecutive non-demented MS patients who completed the BDI-II and the Chicago Multiscale Depression Inventory (CMDI). MS patients also completed a clinical interview, a neurological/neuropsychological examination and a Fatigue Severity Score (FSS) questionnaire in order to assess divergent validity.

Results: The BDI-II showed good internal consistency (Cronbach's alpha 0.89) and good convergent and divergent validity. With respect to CMDI serving as the 'gold standard', the receiver operating characteristic curve revealed that BDI-II is an adequate diagnostic measure and that the optimum total cut-off score was 18.5. Such score identified clinically relevant depressive symptoms in 25.5% of our MS sample.

Conclusions: The BDI-II is a simple, reliable and valid tool for detecting and grading depressive symptoms in Italian MS patients.