Marijuana Use by Patients with Multiple Sclerosis.

BACKGROUND

With social attitudes about marijuana changing and patients sometimes seeking nonmainstream treatment options, the main goal of this study was to investigate the prevalence of, and factors associated with, marijuana use by patients with multiple sclerosis (MS).

METHODS

Adult patients with MS (n = 521) and controls (n = 279) from a study of clinical, neuroimaging, genetic, and environmental factors in MS progression were included. Patients with MS stated whether they had ever used marijuana before MS diagnosis, after MS diagnosis, and in the preceding 3 months as part of an in-person questionnaire. The control group stated whether they had ever used marijuana and in the preceding 3 months.

RESULTS

The percentage of patients with MS reporting ever use of marijuana was 39.9%, compared with 32.7% of controls. Marijuana use in the preceding 3 months was significantly more prevalent among patients with MS (9.4%) compared with controls (0.4%) (

CONCLUSIONS

Patients with MS are more likely to report recent marijuana use than are people without MS. Owing to potential adverse effects, marijuana use by patients with MS may warrant vigilance by MS caregivers, given shifting social attitudes and the trend towards legalization of marijuana in the United States.

Déclaration de conflit d'intérêts

Dr. Weinstock-Guttman has received honoraria for advisory board and educational program service from Teva Pharmaceuticals, Biogen, Novartis, Acorda, EMD Serono, Pfizer, Genzyme, and Sanofi and has also received support for research activities from the National Institutes of Health, National Multiple Sclerosis Society, National Science Foundation, Department of Defense, EMD Serono, Biogen, Teva Neuroscience, Cyberonics, Novartis, Acorda, and the Jog for the Jake Foundation. Dr. Zivadinov has received speaker honoraria and consultant fees from Sanofi Genzyme, Novartis, Claret Medical, and EMD Serono and research support from the Sanofi Genzyme, Claret Medical, Mapi Pharma, Protembis, QuintilesIMS, and Novartis. Dr. Ramanathan has received research funding from the National Multiple Sclerosis Society, the US Department of Defense, and Otsuka Pharmaceutical and compensation for serving as an editor for the American Association of Pharmaceutical Scientists; these are for unrelated research. The other authors declare no conflicts of interest.