CBD reduced seizures in over half of children with drug-resistant epilepsy, with 55% still taking it at 18 months
In 103 pediatric patients with drug-resistant epilepsy, 54% showed reduced seizures at one month, with sustained improvements in communication and alertness, and 55% retention at 18 months.
Quick Facts
What This Study Found
54% of caregivers reported reduced seizure frequency at 1 month; 48% maintained improvement at 2-6 months; communication (60%), alertness (54%), and motor skills (44%) also improved; 55% retention at 18 months; off-label use had higher retention than approved indications.
Key Numbers
103 patients (mean age 11.2); 47% on-label (23 Dravet, 15 LGS, 10 TSC), 53% off-label; retention: 97% at 1 month, 90% at 2 months, 82% at 6 months, 66% at 12 months, 55% at 18 months; 62% positive overall caregiver impression at 1 month.
How They Did This
Prospective study of 103 consecutive pediatric patients starting CBD for drug-resistant epilepsy at a tertiary center (2019-2021); parental questionnaires at 1, 2, and 6 months; retention tracked at 18 months.
Why This Research Matters
Long-term retention data fills a critical gap in understanding whether CBD's initial benefits persist, and the finding that off-label use showed higher retention challenges restrictive prescribing practices.
The Bigger Picture
Together with multicenter retrospective data, this prospective study strengthens the case that CBD benefits extend beyond its three approved epilepsy indications.
What This Study Doesn't Tell Us
Single-center; no control group; caregiver-reported outcomes may introduce bias; dropout by 18 months means retention data may overestimate benefit in completers.
Questions This Raises
- ?Why did off-label patients show higher retention?
- ?Do the non-seizure improvements (communication, alertness) represent direct CBD effects or secondary benefits of seizure reduction?
Trust & Context
- Key Stat:
- 55% of patients were still taking CBD at 18 months, with off-label users showing higher retention
- Evidence Grade:
- Prospective design with consecutive enrollment and long-term follow-up, though single-center and lack of control group limit causal conclusions.
- Study Age:
- Published 2025, enrollment 2019-2021
- Original Title:
- Assessing Real World Efficacy, Safety, and 18-Month Retention Rates of Cannabidiol in Individuals With Drug Resistant Epilepsies.
- Published In:
- European journal of neurology, 32(9), e70304 (2025)
- Authors:
- Chemaly, Nicole(2), Kuchenbuch, Mathieu(2), Losito, Emma, Kaminska, Anna, Coste-Zeitoun, Delphine, Barcia, Giulia, Desguerre, Isabelle, Hully, Marie, Nabbout, Rima
- Database ID:
- RTHC-06193
Evidence Hierarchy
Enrolls participants and follows them forward in time.
What do these levels mean? →Frequently Asked Questions
How many patients stayed on CBD long-term?
55% were still taking CBD at 18 months. Retention decreased gradually from 97% at 1 month to 55% at 18 months.
Did CBD help with anything besides seizures?
Yes. Caregivers reported sustained improvements in communication (60%), alertness (54%), and motor skills (44%) at 2-6 months.
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Cite This Study
https://rethinkthc.com/research/RTHC-06193APA
Chemaly, Nicole; Kuchenbuch, Mathieu; Losito, Emma; Kaminska, Anna; Coste-Zeitoun, Delphine; Barcia, Giulia; Desguerre, Isabelle; Hully, Marie; Nabbout, Rima. (2025). Assessing Real World Efficacy, Safety, and 18-Month Retention Rates of Cannabidiol in Individuals With Drug Resistant Epilepsies.. European journal of neurology, 32(9), e70304. https://doi.org/10.1111/ene.70304
MLA
Chemaly, Nicole, et al. "Assessing Real World Efficacy, Safety, and 18-Month Retention Rates of Cannabidiol in Individuals With Drug Resistant Epilepsies.." European journal of neurology, 2025. https://doi.org/10.1111/ene.70304
RethinkTHC
RethinkTHC Research Database. "Assessing Real World Efficacy, Safety, and 18-Month Retentio..." RTHC-06193. Retrieved from https://rethinkthc.com/research/chemaly-2025-assessing-real-world-efficacy
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.