Marijuana is effective in controlling seizures

Clinical experience and emerging research further indicate that marijuana can help control epileptic seizures.(45) Cannabidiol (CBD), one of the primary (and nonpsychoactive) cannabinoids present in the cannabis plant, appears to be of particular benefit, allowing patients who ingest it at certain times to avoid seizure activity. Some epileptics who cannot tolerate other antiseizure medications have been able to use marijuana to successfully control their seizures, without experiencing debilitating side effects.(46) (See complete APHA amicus brief for footnotes.)

Epilepsy Association of Toronto Regina v. Parker Amicus Brief.

Declaration of Valerie A. Corral, in the landmark medical marijuana case, Conant v. McCaffrey: Ms. Corral is an epilepsy sufferer for whom medical marijuana has proven the only effective treatment for controlling her grand mal seizures and which does so with far fewer side effects than anti-convulsant drugs available through prescription.

Joy, Janet E.; Stanley J. Watson, Jr.; John A. Benson, Jr., Eds. Marijuana and Medicine: Assessing the Science Base. Washington, DC: Division of Neuroscience and Behavioral Health, Institute of Medicine. 1999. 259 p. (Chapter 4 of this report contains a section on epilepsy)