Frequent Cannabis Use Linked to Epilepsy Severity

MONDAY, Sept. 28, 2026 (HealthDay News) — Frequent cannabis use is associated with markers of increased epilepsy severity among patients with drug-resistant epilepsy, according to a study published online Sept. 28 in Epilepsia.

Santiago Philibert-Rosas, M.D., from Washington University in St. Louis, and colleagues examined the association between frequent cannabis use and epilepsy severity, clinical phenotype, and imaging characteristics in a retrospective cohort study involving adults with drug-resistant epilepsy admitted to a tertiary care epilepsy monitoring unit (EMU). Patients were classified based on cannabis use documented in the electronic medical record (64 patients were included: 42 nonusers and 22 frequent users).

The researchers observed an association for frequent cannabis use with shorter time from epilepsy onset to EMU admission, higher prevalence of focal to bilateral tonic-clonic seizures (FBTCS), greater annualized FBTCS frequency, and higher antiseizure medication burden. All frequent cannabis users had temporal lobe epilepsy (TLE), although no significant difference was seen in the prevalence of TLE between the groups. In an imaging analysis, there were no significant group differences noted.

“Right now, the honest answer when a patient asks whether their cannabis use is affecting their seizures is that we”re not sure,” Philibert-Rosas said in a statement. “Larger studies will help us give them a real answer — how much matters and whether stopping helps — so they can make an informed decision.”

Abstract/Full Text