Epilepsy Foundation Position:

  • The Epilepsy Foundation supports the rights of patients and families living with seizures and epilepsy to access physician directed care, including medical marijuana.
  • The Epilepsy Foundation calls for an end to Drug Enforcement Administration (DEA) restrictions that limit clinical trails and research into medical marijuana for epilepsy.
  • The Epilepsy Foundation believes that an end to seizures should not be determined by one’s zip code.

Read further details describing our position on medical marijuana along with a statement from President and CEO Phil Gattone & Board Chair Warren Lammert and commentary from Dr. Orrin Devinsky.


What to do about the medical use of marijuana (cannabis) as a potential treatment for a number of neurologic conditions, including epilepsy, is a hotly debated issue. There are legal issues surrounding its dispensing and prescription, as well as a lack of scientific research on the usefulness and safety of marijuana as a treatment for seizures. Here are four commonly asked questions about this dilemma:

Does marijuana help seizures?

Evidence from laboratory studies, anecdotal reports, and a small clinical study from a number of years ago suggests that cannabidiol, a non-psychoactive compound of cannabis, could potentially be helpful in controlling seizures. However, there are conflicting reports in the literature. So far, no clear, definitive, solid evidence exists to show marijuana helps seizures.

Does marijuana have side effects on seizures?

Marijuana has a number of effects depending on how it is ingested:

  • If smoked, the risk factors associated with smoking apply to marijuana.

  • If one takes marijuana preparations that are not smoked, side effects are similar to ones that would be seen with inhaled varieties of the drug. These include appetite stimulation and memory problems.

  • It is difficult to assess the adverse effects of the drug since there is no controlled amount of the medication that has been studied. Therefore, other side effects could occur that are simply not known yet to practicing physicians.

What are the laws governing medical marijuana?

A number of states in the U.S. have statutes allowing for dispensation and prescription of this substance. However, the federal government also has a law that is contradictory and fundamentally criminalizes its use. Therefore, if physicians choose to follow the state laws on the medical use of marijuana, it does not guarantee that they will be immunized against federal prosecution for prescribing the medication if the federal government were to decide to enforce these laws. Therefore, physicians must be aware of both federal and state laws and the potential implications. A clearer understanding of the laws governing this issue is needed.

Should one pursue medical marijuana if all other medications do not work?

The goal of epilepsy treatment is to stop seizures with minimal or no side effects. There are receptors in the brain for marijuana, otherwise known as cannabinoid receptors, in areas that are commonly known to cause seizures (such as the hippocampus and amygdala). There is very little understanding as to what roles these receptors play in seizures. Given the legal issues, the lack of clarity on side effects, and risks associated with the use of the medication, there are better options one could try for epilepsy before resorting to marijuana.

Perhaps a clinical drug trial for a new medication or alternatively a new device may be more appropriate and—to some degree— a bit safer. For new medicines or devices, there are federal governing agencies monitoring the safety of the compound and/or device.

To date, there is very little to no monitoring of street-based marijuana. Therefore, one takes risks into their own hands and sometimes this can lead to terrible consequences. But since medical marijuana is now legal in many states, suppliers are working hard to develop dependable branded product, even mixes carefully controlled to offer specific percentages of THC or CBD.

The Epilepsy Foundation supports research on the potential antiepileptic effects of CBD or other marijuana.  While there is experimental evidence that CBD can work to stop seizures in animal models and there are reports that it may be effective in patients with epilepsy, there is a lack of scientific data in humans.  The Epilepsy Foundation urges anyone exploring  epilepsy treatments, as permitted under their state law, to work with their treating physician to make the best decisions for their own care.

More about the studies on marijuana and epilepsy:

There are current ongoing trials involving cannabis for epilepsy, such as one at NYU which is sponsored by the Epilepsy Foundation.

While there are no studies finding that either marijuana or its active metabolite, tetrahydrocannabinol, may worsen seizures, there is no scientific basis to justify such studies.

One case-controlled study was designed to evaluate illicit drug use and the risk of a first seizure. Investigators concluded that marijuana is protective against the first-time seizure in men but not women.

  • This study compared 308 individuals who had been admitted to a hospital after their first seizure with a control group of 294 patients. The control group was made up of patients who had not had seizures and were admitted for emergency surgery such as appendicitis, etc.

  • Compared to men who did not use marijuana, the odds of a first seizure for men who had used marijuana within 90 days of hospital admission were roughly 3.6 out of 10.

  • The results for women were not statistically significant. Nevertheless, the study was weak, because it did not include measures of health status prior to hospital admission for the patients' serious conditions.

The potential anti-epilepsy activity of marijuana and its metabolites has been investigated, but so far, the data has not been promising.

  • There have been 3 controlled trials in which marijuana substances were given orally to patients who had had generalized grand mal seizures or focal seizures. These studies were small and the largest study involved 12 patients. One study was a double-blind, placebo-controlled trial in which 8 patients with epilepsy were given marijuana in addition to their standard therapy. Another was a double-blind, placebo-controlled trial in which 12 patients with epilepsy were given marijuana along with their standard anti-epileptic therapy, and then a third one was a double-blind, placebo-controlled add-on crossover trial with 10 patients.

  • In two of the studies, marijuana had no effect on seizure frequency; however, in one of the studies, four of eight patients had significant improvement.

  • Two of the studies were never published and one was presented as an abstract. The studies are so small that one cannot make any definite conclusion about the effect of marijuana as a seizure treatment.

by Joseph I. Sirven, MD
Chair, Epilepsy Foundation Professional Advisory Board

Editor-in-Chief, epilepsy.com
Originally Published: 9/15/11
Revised: February, 2014

Reviewed by: Joseph I. Sirven, MD | Patricia O. Shafer, RN, MN on 3/2014
Dr. Orrin Devinsky