Ask Dr. Leigh: Can cannabis help with seizures?


Using cannabis can have a big impact on your physical and mental health—for better, and sometimes for worse. That’s why it’s important to consult a healthcare provider before experimenting.

Here at GreenState, cannabis clinician Dr. Leigh Vinocur is here to answer your questions on healthy living with cannabis.

Editor’s Note: The answer to this question is meant to supplement, not replace, advice, diagnoses, and treatment from a healthcare provider.  Always consult a medical professional when using cannabis for medicinal purposes, and do not disregard the advice of your healthcare provider because of anything you may read in this article. 

Q: Can cannabis help with my seizures?

A: Epilepsy is a condition that often leads people to seek out cannabis as a treatment.

Epilepsy is a broad term for a brain disease that causes seizures.  A seizure is a change in normal brain activity which results in a sudden uncontrolled abnormal burst of electrical activity resulting in changes in behavior and/or consciousness. Some are just staring spells, while some result in loss of consciousness as well as falling down with violent shaking and jerking muscle activity. Generalized seizures involve the whole brain, while focal seizures involve only one area of the brain.

According to the Centers for Disease Control and Prevention (CDC), the incidence of epilepsy affects about 1.2 percent of the US population about 3.4 million people, 3 million adults, and around 470,000 children. It is the fourth most common neurologic condition in the US. Approximately 30 percent of all epilepsy patients have the drug-resistant form, with 20 percent of those being pediatric epilepsy patients. Drug-Resistant Epilepsy (DRE) is defined as failure to respond to therapy after trying two or more anti-epileptic drugs (AED) whether individually or in combination to achieve sustained seizure freedom. This is often the reason people look to cannabis for help.

A recent small study done at Oregon Health & Science University after the state legalized adult use found that over 87 percent of the respondents to their survey reported using cannabis to treat their epilepsy.

The theory behind cannabis helping with seizures is that our internal endocannabinoid system (ECS) is integral to maintaining balance and calming our central nervous system. Our ECS plays a protective role in calming the overexcitation of nerve cells that we see in seizure disorders.

There is compelling scientific evidence that an ECS deficiency and/or dysfunction could lead to seizures. Research done in 2008 found ECS abnormalities related to cannabinoid receptors (CB1) in epileptic brains when compared to normal brain tissue on autopsy. Another study around that time looked at brain tissue cultures and showed that blocking CB1 receptors produced continuous seizure activity with nerve cell firing. This is analogous to a serious condition called status epilepticus, which is abnormally prolonged seizure activity that is very hard to control and can be life-threatening.  Another study from 2010 found there are lower levels of our internal endocannabinoid anandamide, which is a neurochemical produced to calm the nerves in our brain, in newly diagnosed untreated patients with epilepsy.

Cannabidiol (CBD) is probably the most researched cannabinoid for the treatment of seizures. For children who have severe, drug-resistant seizure disorders associated with 3 rare congenital conditions (Dravet syndrome, Lennox-Gastaut syndrome, and Tuberous sclerosis) the FDA approved a drug called Epidiolex in 2018. It is the first plant-based, non-synthetic cannabis drug ever approved. It is almost pure cannabidiol (CBD). The studies were done by the UK company GW Pharmaceuticals, and they found that over 50 percent of patients experienced a 50 percent reduction in seizures after using this drug.

Aside from the clinical trials done for Epidiolex approval, other studies published in the journal Epilepsia have also shown that CBD can have a key protective role in calming the overexcitation of nerve impulses seen in seizures.  CBD has anti-inflammatory and neuroprotective effects that can help with seizure disorders.  And according to more recent research, it can work at multiple receptor sites in the brain to inhibit nerves from firing with overexcitation. It can promote the brain’s inhibition chemical called GABA-a, known to decrease the nerves from over-transmitting impulses which are often seen in seizures. It can also enhance and promote anandamide which then can calm the nerves and prevent overexcitation.

When it comes to THC there are mixed results related to its antiseizure activity. Some animal studies particularly those done on healthy animals find that THC can actually promote seizures, especially in high doses. But there are some studies that found it could decrease a chemical in the brain called glutamate which is known to excite the nerve cells and promote seizures. Some seizure patients have found that low doses of THC combined with CBD or tetrahydrocannabinolic acid (THCA) can be helpful.

THCA is the acidic cannabinoid which is the precursor form of THC found in live fresh plants. But after drying or heating it is converted to its neutral, non-acidic form—THC. An old study done in mice in the 1980s showed THCA could reduce seizures in high doses.

Other minor cannabinoids found in cannabis and hemp such as cannabidiolic acid (CBDA), which is the acidic precursor form of CBD, have been found to have similar effects to CBD. When studied by GW Pharmaceuticals in animals, it seemed to have better absorption when taken orally. They also looked at another minor cannabinoid called cannabidivarin (CBDV) and they found it can also promote anandamide to help calm down the central nervous system. It had additive effects when used with CBD but was not that beneficial when used alone even in high doses. Another study also found it useful as an add-on therapy for focal seizures.

Before starting to use cannabis for a seizure disorder, make sure you speak with your physicians. It’s important to get blood tests and to pay close attention to your anti-seizure drug levels while using cannabis.  Because cannabis can interfere with the metabolism of some prescription medications, it can cause toxic levels of your anti-seizure medicines to accumulate in your body.

Got cannabis questions? Ask Doctor Leigh. Send your questions to GreenState’s Managing Editor Elissa Esher at and keep an eye out for new answers from Dr. Leigh Vinocur every month.

Dr. Leigh Vinocur is a board-certified emergency physician who also has a cannabis consulting practice for patients and industry. She is a member of the Society of Cannabis Clinicians and a graduate of the inaugural class, with the first Master of Science in the country in Medical Cannabis Science and Therapeutics from the University of Maryland School of Pharmacy.

For more advice from Dr. Leigh and other cannabis-informed healthcare professionals Dr. Leslie Matthews and Dr. Hal Altman, listen to “Cannabis Grand Rounds” here: 

The response to this question was not written or edited by Hearst. The authors are solely responsible for the content.

Leigh Vinocur, MD