CBD showed similar effectiveness for rare genetic epilepsies whether used on-label or off-label

In 266 patients with 77 different monogenic epilepsies, nearly half achieved 50% or greater seizure reduction with CBD, with no difference between approved and off-label uses.

Cerulli Irelli, Emanuele et al.·Epilepsia·2025·Strong EvidenceRetrospective Cohort
RTHC-06177Retrospective CohortStrong Evidence2025RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Retrospective Cohort
Evidence
Strong Evidence
Sample
N=266

What This Study Found

47.5% of patients achieved 50% or greater seizure reduction; 7.4% became seizure-free; no significant difference between approved indications and off-label use; shorter prior seizure-free periods and greater intellectual disability predicted lower effectiveness.

Key Numbers

266 patients (135 female); 77 different monogenic epilepsies; median age at CBD start 12 years; 47.5% achieved 50%+ seizure reduction; 7.4% seizure-free; 65.8% showed Clinical Global Impression improvement; median follow-up 17 months.

How They Did This

Retrospective multicenter study across 27 epilepsy centers; 266 patients with monogenic epilepsies treated with highly purified CBD for at least 3 months; median follow-up 17 months.

Why This Research Matters

CBD is only approved for three specific epilepsy syndromes, but this large real-world study suggests comparable effectiveness across a much wider range of genetic epilepsies.

The Bigger Picture

This provides the strongest evidence yet that CBD's antiseizure effects extend well beyond Dravet, Lennox-Gastaut, and tuberous sclerosis syndromes.

What This Study Doesn't Tell Us

Retrospective design; no control group; variable dosing and co-medications across centers; potential selection bias toward patients expected to respond.

Questions This Raises

  • ?Which specific genetic epilepsies respond best to CBD?
  • ?Should regulatory approvals expand to include more monogenic epilepsies?
  • ?Can genetic markers predict CBD response?

Trust & Context

Key Stat:
47.5% achieved 50%+ seizure reduction across 77 different monogenic epilepsies
Evidence Grade:
Large multicenter real-world study with meaningful follow-up, though retrospective design and lack of control group limit causal claims.
Study Age:
Published 2025
Original Title:
Expanding the therapeutic role of highly purified cannabidiol in monogenic epilepsies: A multicenter real-world study.
Published In:
Epilepsia, 66(7), 2253-2267 (2025)
Database ID:
RTHC-06177

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-ControlFollows or compares groups over time
This study
Cross-Sectional / Observational
Case Report / Animal Study

Looks back at existing records to find patterns.

What do these levels mean? →

Frequently Asked Questions

Did CBD work as well for off-label epilepsies as for approved ones?

Yes. There was no significant difference in seizure outcomes between patients using CBD for its approved indications versus off-label genetic epilepsies.

What predicted poorer response to CBD?

Shorter maximum seizure-free periods before starting CBD and greater intellectual disability were both associated with lower effectiveness.

Read More on RethinkTHC

Cite This Study

RTHC-06177·https://rethinkthc.com/research/RTHC-06177

APA

Cerulli Irelli, Emanuele; Mazzeo, Adolfo; Caraballo, Roberto H; Perulli, Marco; Moloney, Patrick B; Peña-Ceballos, Javier; Rubino, Marica; Mieszczanek, Katarzyna M; Santangelo, Andrea; Licchetta, Laura; De Giorgis, Valentina; Reyes Valenzuela, Gabriela; Casellato, Susanna; Cesaroni, Elisabetta; Operto, Francesca F; Domínguez-Carral, Jana; Ramírez-Camacho, Alia; Ferretti, Alessandro; Santangelo, Giuseppe; Aledo-Serrano, Angel; Rüegger, Andrea; Mancardi, Maria M; Prato, Giulia; Riva, Antonella; Bergonzini, Luca; Cordelli, Duccio M; Bonanni, Paolo; Bisulli, Francesca; Di Gennaro, Giancarlo; Matricardi, Sara; Striano, Pasquale; Delanty, Norman; Marini, Carla; Battaglia, Domenica; Di Bonaventura, Carlo; Ramantani, Georgia; Gardella, Elena; Orsini, Alessandro; Coppola, Antonietta. (2025). Expanding the therapeutic role of highly purified cannabidiol in monogenic epilepsies: A multicenter real-world study.. Epilepsia, 66(7), 2253-2267. https://doi.org/10.1111/epi.18378

MLA

Cerulli Irelli, Emanuele, et al. "Expanding the therapeutic role of highly purified cannabidiol in monogenic epilepsies: A multicenter real-world study.." Epilepsia, 2025. https://doi.org/10.1111/epi.18378

RethinkTHC

RethinkTHC Research Database. "Expanding the therapeutic role of highly purified cannabidio..." RTHC-06177. Retrieved from https://rethinkthc.com/research/cerulli-2025-expanding-the-therapeutic-role

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.