Does L-Amphetamine Improve Memory in Cognitively Impaired Multiple Sclerosis Patients?

In 2009, researchers conducted an industry-funded, randomized, placebo-controlled trial of oral l-amphetamine (30 mg/day) in 136 patients who had previously-documented cognitive impairment related to multiple sclerosis (MS) (J Neurol 2009; 256:1095). After 29 days, the drug was no better than placebo at improving performance on the Symbol Digit Modalities Test (SDMT; the primary outcome) or on the Paced Auditory Serial Addition Test (PASAT), but it did show advantages over placebo for secondary outcomes on auditory and visual learning (the California Verbal Learning Test II [CVLT-II] and the Brief Visuospatial Memory Test—Revised [BVMTR], respectively).

In this industry-funded reanalysis, the investigators stratified the participants accordi…