Study Period: 6 to 12-month competitive enrollment period, two groups (Avonex and Avonex +Provigil 200 mg QD ) undergo baseline (prior to starting Provigil), 2-month, and 4-month neuropsychological evaluations. Total length of study, once initiated, (including 2 month preparation period, 6 to 12-month competitive enrollment period through final four-month visit) is 12 to 18 months.