Description: This is a phase II study for people with multiple sclerosis who have cognitive impairment. Volunteers 18-64 who have at least a 9th grade education and a diagnosis of MS (relapsing remitting or secondary progressive) may be eligible. Candidates will be ineligible if they have memory deficits caused by significant neurological/psychological disorders, major depressive disorder, or are taking certain medications, including tricyclic antidepressants, antipsychotics, Strattera, or CNS stimulants.