CBD kept working for over 86% of children with severe epilepsy through two years, with nearly 80% seeing seizures cut in half | Research

The takeaway

In a retrospective study of 29 pediatric patients with intractable epilepsy, adjunctive CBD therapy showed retention rates above 86% at both 12 and 24 months, with 79.3% achieving at least 50% seizure reduction at one year.

Families of children with treatment-resistant epilepsy, pediatric neurologists, and researchers studying CBD across epilepsy subtypes.

79.3% achieved 50%+ seizure reduction at 12 months

What the researchers found

At 12 months, 79.3% of patients achieved 50% or greater seizure reduction and 34.5% achieved 75% or greater reduction without generalized motor seizures. The retention rate exceeded 86% at both 12 and 24 months. One patient with a GABRB3 variant achieved seizure freedom.

Why it matters

Children with intractable epilepsy have often exhausted conventional treatment options. This study shows CBD maintained effectiveness across a range of genetic and non-genetic epilepsy causes, including some rarely studied variants.

The numbers in context

29 patients. Median maintenance dose 14.2 mg/kg/day. Retention above 86% at 12 and 24 months. 79.3% achieved 50%+ seizure reduction at 12 months. 34.5% achieved 75%+ reduction. Adverse events in 37.9%, mostly somnolence and lethargy. 3 discontinuations.

How the study worked

Retrospective cohort study of 29 patients aged 6-24 years with pediatric-onset intractable epilepsy treated at Korea University Hospitals between April 2019 and May 2024. Median follow-up was 14.3 months. Patients were on a median of 5 antiseizure medications at CBD initiation.

What this study cannot tell us

Retrospective design with a small sample of 29 patients. Single center in South Korea. No control group. Patients were on multiple concurrent medications, making it difficult to isolate CBD effects.

How to read the evidence

Moderate: retrospective cohort with reasonable follow-up duration but small sample, no control group, and single-center design.

When this study was published

Published 2026. Data from April 2019 to May 2024.

The bigger picture

Most CBD epilepsy research focuses on Dravet and Lennox-Gastaut syndromes. This study extends the evidence across diverse etiologies including GABRB3, SCN2A, KCNT1, and KIF1A variants, Angelman syndrome, and acquired causes like hypoxic brain injury.

Questions still open

Which genetic epilepsy subtypes respond best to CBD? Could earlier introduction of CBD (before trying 5+ medications) improve outcomes? What explains the high retention rate compared to other antiseizure medications?

Common questions

How effective is CBD for treatment-resistant epilepsy in children?

In this study of 29 patients with intractable epilepsy, 79.3% achieved at least 50% seizure reduction at 12 months with adjunctive CBD therapy.

Does CBD work for different types of epilepsy?

This study found favorable results across diverse causes including SCN1A, GABRB3, and SCN2A variants, Angelman syndrome, cortical dysplasia, and acquired brain injuries.

Read the original research

Adjunctive cannabidiol in intractable pediatric epilepsy: A retrospective study on tolerability, efficacy, and safety across genetic and nongenetic etiologies.

Medicine, 105(5), e47425

View on PubMed ↗Publisher’s paper ↗

Citation

Shim, Youngkyu; Yang, Dong Hwa; Byeon, Jung Hye; Eun, Baik-Lin. (2026). Adjunctive cannabidiol in intractable pediatric epilepsy: A retrospective study on tolerability, efficacy, and safety across genetic and nongenetic etiologies.. Medicine, 105(5), e47425. https://doi.org/10.1097/MD.0000000000047425