Relationship between the Montgomery-Åsberg Depression Rating Scale and Sheehan Disability Scale in patients with bipolar depressive episodes.

Objective: To examine the relationship between depressive symptoms and daily functioning among patients with bipolar depression using the Montgomery-Åsberg Depression Rating Scale (MADRS) and Sheehan Disability Scale (SDS).

Methods: A post-hoc analysis was conducted using data from a placebo-controlled study of lurasidone involving 399 patients with bipolar depression. Pearson's correlation coefficient was used to analyse the correlation between the MADRS and SDS total scores. Receiver operating characteristic (ROC) analysis determined the MADRS cut-off score for adequate functional improvement, defined as all SDS subscale scores ≤2.

Results: The MADRS and SDS scores were positively correlated (r = 0.764). The ROC analysis yielded a MADRS cut-off score of 15.5 for adequate functional improvement with 86.9% sensitivity and 75.9% specificity. The wide distribution of the relationship observed between symptoms and functioning indicated diversity in treatment responsiveness in bipolar depression.

Conclusions: Depressive symptoms and daily functioning are correlated; however, this relationship is not straightforward, highlighting the need for evaluating symptoms and functioning separately. Importantly, direct application of the statistical MADRS threshold in clinical practice may be inappropriate for estimating SDS-based functioning. Further research is needed to establish norms linking levels of symptoms and functioning in bipolar depression.