Interferon beta 1-b in verbal memory functioning of patients with relapsing-remitting multiple sclerosis.

The effects of interferon Beta 1-b (Betaseron) on verbal memory functioning was examined in 167 patients with relapsing-remitting multiple sclerosis and 112 matched normal controls. Subjects were administered 10 verbal memory tests from the Memory Assessment Scales and the Verbal subtests from the Wechsler Adult Intelligence Scale. Analysis showed subjects treated with Betaseron (n = 73) did not perform significantly better on measures of verbal memory or verbal ability than subjects not receiving the drug (n = 94), although the mean performance of treated subjects was higher across all verbal memory tests. Both groups of patients performed significantly worse on verbal memory subtests measuring list acquisition, delayed list recall, delayed cued recall, and the immediate and delayed recall of names and faces than control subjects. Although patients had lower performance scores across all memory tests than the control subjects, their scores were not within the impaired range. These results do not permit a clear conclusion about the effects of Betaseron on verbal memory for any effect is probably obscured by the relatively preserved cognitive functioning of this outpatient sample.