Dec. 12, 2003 (Boston) — People with epilepsy are more than twice as likely to use marijuana as the general population, according to a telephone survey conducted by researchers at the University of Alberta in Edmonton, Canada.

Donald W. Gross, MD, said about 21% of patients who answered the survey had used marijuana during the previous year, and 8% had used it every other day or more. In comparison, he quoted data from the National Household Survey on Drug Abuse and a Canadian survey, which put use during the previous year at 8.9% in the general population.

He and Daphne Quigley, BScN, nurse coordinator of the Adult Epilepsy Program at the University of Alberta Hospital, presented the study in a poster here at the 57th annual meeting of the American Epilepsy Society.

More surprising, he said, was that 24% of 136 respondents — including those who did not use marijuana — contended that marijuana is effective in the treatment of seizures. Despite studies showing cannabinoids can help control seizures in animals, no clinical studies have been conducted in humans, according to Dr. Gross.

In an interview at the poster session, Dr. Gross said his group undertook the survey because patients often told him marijuana was effective in controlling seizures or asked about reports that the drug could be helpful.

In the study, about two thirds of 28 active users said it helped control their seizures: 19 reported improvement in seizure severity, and 15 in seizure frequency. No one said that seizures worsened, but nine respondents said marijuana had no effect on severity of seizures and 13 said it did not help reduce frequency.

Analysis of the responses showed that marijuana use in the study population did not correlate to most factors usually associated with recreational drug use: male sex, youth, and unemployment, according to Dr. Gross. The exception was use of other illicit drugs.

Marijuana use did correlate with more frequent seizures and longer history of epilepsy. "So from our perspective we felt marijuana use in our population was more consistent with a nonconventional healthcare choice than recreational drug use," he said, calling for clinical studies to evaluate whether marijuana is effective in seizure control.

This study received no external funding.

AES 57th Annual Meeting: Abstract 2.314. Presented Dec. 9, 2003.

Reviewed by Gary D. Vogin, MD

http://www.medscape.com/viewarticle/465891