The behavioral manifestations associated with MS include both cognitive and emotional disturbances. Overall intellect is slightly affected in about half of patients, and 20% to 33% demonstrate more severe impairments. Memory disturbances are particularly common, and retrieval function is especially affected. Difficulties with concept formation and other executive functions can be subtle yet have significant impact on daily living. Depression is frequent in MS, sometimes despite an outward euphoria that is more prevalent with advancing disease. Psychosis occurs rarely, but bipolar disorder is more frequent than in the general population. MS may be associated with a variety of personality changes, but it is impossible to generalize about this or to identify an "MS personality." Disturbances of emotional control are relatively frequent. Comprehensive management of these problems uses multiple modalities including good neurologic care, cognitive rehabilitation, counseling and support groups, and pharmacotherapy.