The goal of the study is to evaluate the effectiveness of Cannabidiol (CBD) as an adjunct treatment in the reduction of seizure frequency in DRE patients of various etiologies.

Epilepsy affects approximately 70 million people globally, with one-third experiencing drug-resistant epilepsy (DRE). CBD has shown promise in reducing seizure frequency for specific epilepsy syndromes, though data for broader etiologies remain limited.

We conducted a retrospective chart review of patients with refractory epilepsy who received a CBD as an adjunct treatment at two tertiary care centers. Seizure frequency at the start of CBD treatment and at a minimum follow-up of 3 months was recorded. Epilepsy diagnosis was categorized into five groups: Focal/Multifocal Epilepsy, Primary Generalized Epilepsy, Lennox-Gastaut Syndrome, Dravet Syndrome, and Other Developmental and Epileptic Encephalopathies.

Among all patients, 49% achieved a ≤25% reduction in seizures, while 5% had a 26-50% reduction, 21% reached a 51-75% reduction, 20% experienced a 76-99% reduction, and 5% achieved near seizure freedom. There was a significant reduction in median seizure frequency from 30 at baseline to 8 post-treatment (p = 0.000). Significant reductions in seizure frequency were also observed within each diagnostic category.

CBD has proven to be an effective adjunctive treatment for medically refractory epilepsy, showing significant efficacy across various epilepsy etiologies and genetic backgrounds. Its ability to reduce seizure frequency and the burden of antiseizure medications (ASMs), especially in syndromes that are traditionally difficult to manage, highlights its value as an additional therapeutic option.