How the conflict between American psychiatry and neurology delayed the appreciation of cognitive dysfunction in multiple sclerosis.

Whereas cognitive deficits in multiple sclerosis (MS) were documented in the original clinicopathological description by Charcot, the extent and nature of cognitive dysfunction was poorly understood in the U.S. until over a century later. Our objective was to discern reasons for this misunderstanding and to examine forces shifting this topic to center stage of research and increased awareness in clinical practice. We hypothesized that during the 19th century, conflict between psychiatrists and neurologists over control of treatment of the mentally ill fueled a misunderstanding of the nature of MS which led neurologists to treat diseases of the body, and psychiatrists, diseases of the mind. The importance of cognitive deficits in MS was thus minimized until scientific breakthroughs could once again bring them to light. As the rift between disciplines peaked, awareness of cognitive deficits diminished, and vice versa. This may have been one contributing factor affecting how MS was mistakenly conceptualized for a century.