Psychiatric comorbidity common, but relationship may be bidirectional

Psychiatric disorders were associated with subsequent neurologic severity in multiple sclerosis (MS) patients and could potentially be causative, a retrospective cohort study in Canada suggested.

Mood and anxiety disorders were linked to a higher Expanded Disability Status Scale (EDSS) score in MS patients over an average of 10 years of follow-up, reported Ruth Ann Marrie, MD, PhD, of the University of Manitoba in Winnipeg, Canada, and colleagues, online in Neurology.

“These findings emphasize the importance of using a systematic approach to identify psychiatric comorbidity in people with MS and to ensure effective treatment,” Marrie told MedPage Today.

“Psychiatric comorbidity is very common in MS. It’s well recognized to adversely affect quality of life, but the effects on disability progression had been poorly understood. We showed that the presence of psychiatric comorbidity increased the severity of disability progression.”

The relationship may be bidirectional, Marrie added: For some, a psychiatric condition may either develop, or be diagnosed more easily, as disability worsens. Further testing could help establish the direction of the association and provide evidence of the effect of psychiatric treatment on MS disability.