Diagnosing Depression in MS in the Face of Overlapping Symptoms.

Depression is an important problem in multiple sclerosis (MS), but the diagnosis is challenging since symptoms of depression overlap with those of MS. In the past, the main strategy has been to remove physical symptoms from scales assessing depressive symptoms in MS, but these attempts have not been successful. Depression and overlapping MS symptoms may actually share pathophysiological mechanisms, so the strategy of attempting to exclude such symptoms may be fundamentally flawed. Current diagnostic criteria provide a pragmatic solution, but it may be possible to develop improved definitions.