CBD kept working for over 86% of children with severe epilepsy through two years, with nearly 80% seeing seizures cut in half
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.
Quick Facts
What This Study 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.
Key Numbers
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 They Did This
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.
Why This Research 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 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.
What This Study Doesn't 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.
Questions This Raises
- ?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?
Trust & Context
- Key Stat:
- 79.3% achieved 50%+ seizure reduction at 12 months
- Evidence Grade:
- Moderate: retrospective cohort with reasonable follow-up duration but small sample, no control group, and single-center design.
- Study Age:
- Published 2026. Data from April 2019 to May 2024.
- Original Title:
- Adjunctive cannabidiol in intractable pediatric epilepsy: A retrospective study on tolerability, efficacy, and safety across genetic and nongenetic etiologies.
- Published In:
- Medicine, 105(5), e47425 (2026)
- Authors:
- Shim, Youngkyu, Yang, Dong Hwa, Byeon, Jung Hye, Eun, Baik-Lin
- Database ID:
- RTHC-08620
Evidence Hierarchy
Looks back at existing records to find patterns.
What do these levels mean? →Frequently Asked 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.
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Cite This Study
https://rethinkthc.com/research/RTHC-08620APA
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
MLA
Shim, Youngkyu, et al. "Adjunctive cannabidiol in intractable pediatric epilepsy: A retrospective study on tolerability, efficacy, and safety across genetic and nongenetic etiologies.." Medicine, 2026. https://doi.org/10.1097/MD.0000000000047425
RethinkTHC
RethinkTHC Research Database. "Adjunctive cannabidiol in intractable pediatric epilepsy: A ..." RTHC-08620. Retrieved from https://rethinkthc.com/research/shim-2026-adjunctive-cannabidiol-in-intractable
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.