Mood disorders in multiple sclerosis and the effects on cognition.
BACKGROUND
Depression and cognitive dysfunction are common in patients with multiple sclerosis. However, it is unclear whether depression may cause or exacerbate cognitive problems as data remain equivocal. The current review attempts to clarify the relationship between these behavioral disorders.


METHODS
The literature pertaining to the influence of depression on cognition in MS patients has been reviewed.


RESULTS
Early studies consistently failed to find an association and concluded that cognitive dysfunction in MS patients occurred independently of depression. A more recent literature has found fault with this, citing numerous methodological flaws in the studies undertaken. Newer data now suggests that core symptoms of depression reduce cognitive capacity, in particular exerting an adverse effect on the executive function component of working memory.


CONCLUSIONS
Depression may exacerbate cognitive dysfunction in MS patients. Whether treating depression will lead to cognitive improvement is not yet known, but warrants further exploration.
Feinstein
Anthony
A
Department of Psychiatry, University of Toronto, Sunnybrook and Women's College Health Sciences Centre, 2075 Bayview Avenue, Toronto, ON, Canada M4N 3M5. antfeinstein@aol.com
D003071:Cognition / Q000502:physiology*; D003863:Depression / Q000209:etiology; D006801:Humans; D019964:Mood Disorders / Q000503:physiopathology*; D009103:Multiple Sclerosis / Q000503:physiopathology*