Frequent Marijuana Use Tied To More Severe Epilepsy

A new study suggests frequent marijuana use may worsen seizures in people with hard-to-treat epilepsy.

“There isn’t definitive data that cannabis use worsens epilepsy,” senior author Dr. Aaron Struck, an associate professor of neurology at WashU Medicine in St. Louis, said in a news release. 

“But if someone is using cannabis to help with anxiety or sleep,” he added, “I’d prefer to treat those problems with drugs we understand rather than something largely unregulated whose impact on the brain we don’t really know.”

Researchers reviewed the medical records of 64 adults with drug-resistant epilepsy who were admitted to an inpatient unit where doctors monitored their seizures in real time.

Twenty-two of them reported using marijuana at least 20 days a month.

The difference between the two groups was significant. In all, 91% of frequent users experienced convulsive seizures compared with 57% of nonusers.

Frequent users also had more than twice as many convulsive seizures per year and became resistant to antiseizure drugs faster.

On average, they needed specialized inpatient monitoring to adjust medications or consider surgery just five years after their first seizure. That compared with 18 years for nonusers.

While these findings show a link between cannabis use and seizures, they don’t prove cause and effect, which is why researchers plan a follow-up study to help patients understand their risk.

“Larger studies will help us give them a real answer — how much matters and whether stopping helps — so they can make an informed decision,” said first author Dr. Santiago Philibert Rosas, a research specialist in Struck’s lab at Washington University in St. Louis.

The study was published in the journal Epilepsia.

More information

The Epilepsy Foundation has more on epilepsy.

SOURCE: HealthDay TV, Sept. 28, 2026