Making the scientific case for testing CBD in treatment-resistant epilepsy | Research

The takeaway

Pure CBD showed strong anticonvulsant properties in animal models and appeared well tolerated in humans, making it an ideal candidate for clinical trials in treatment-resistant epilepsy.

Read this if you want to understand the scientific reasoning that led to CBD being tested and approved for epilepsy.

Strong preclinical anticonvulsant evidence supported systematic CBD clinical trials

What the researchers found

This editorial-style review from leading epilepsy researchers argued that pure CBD had accumulated sufficient preclinical evidence to justify systematic clinical investigation for treatment-resistant epilepsy. Basic research had demonstrated strong anticonvulsant effects in acute animal models, though data from chronic models was limited.

CBD appeared to be well tolerated in available human data, and importantly, it lacked the psychotropic effects of THC that limit tolerability. Previous human epilepsy studies had been small and methodologically limited, with inconclusive results. Recent anecdotal reports of high-CBD medical marijuana showed promise but lacked controlled conditions.

The authors called for systematic safety, pharmacokinetic, and drug interaction studies as a foundation for double-blind, placebo-controlled efficacy trials, particularly targeting Dravet and Lennox-Gastaut syndromes.

Why it matters

This paper, authored by researchers who would go on to lead the pivotal CBD epilepsy trials, laid the intellectual groundwork for the clinical development program that ultimately led to FDA approval of Epidiolex in 2018.

The numbers in context

No specific trial data were reported. The review cited strong preclinical anticonvulsant evidence and limited but promising human data. Target populations identified: Dravet syndrome and Lennox-Gastaut syndrome.

How the study worked

Expert review and commentary on the state of evidence for CBD in epilepsy, including preclinical data, available human evidence, and proposed clinical trial strategy.

What this study cannot tell us

The anticonvulsant mechanisms of CBD were not fully understood. Human evidence was limited to small, methodologically weak studies and anecdotal reports. Drug interactions between CBD and existing antiepileptic medications were unknown.

How to read the evidence

Expert review summarizing the evidence base and calling for rigorous clinical trials. The subsequent trials confirmed the premise.

When this study was published

Published in 2014, four years before FDA approval of CBD (Epidiolex) for epilepsy in 2018.

The bigger picture

This review appeared at a crucial moment in cannabinoid medicine. Public demand for CBD-based epilepsy treatments was growing rapidly, while scientific evidence remained limited. The authors bridged the gap between public enthusiasm and scientific rigor by outlining a systematic path to controlled clinical evidence.

Questions still open

All questions raised by this paper were subsequently addressed by clinical trials: CBD was proven effective for Dravet and Lennox-Gastaut syndromes and received FDA approval in 2018.

Common questions

Did CBD get approved for epilepsy?

Yes. This 2014 review called for the clinical trials that were subsequently conducted. Pure CBD (Epidiolex) received FDA approval in 2018 for Dravet syndrome and Lennox-Gastaut syndrome, two severe forms of treatment-resistant epilepsy.

How is CBD different from marijuana for epilepsy?

CBD is the non-psychoactive component of cannabis. Unlike THC, it does not produce a "high." This review argued that pure CBD, isolated from the rest of the cannabis plant, was the ideal candidate for rigorous epilepsy testing.

Read the original research

The case for assessing cannabidiol in epilepsy.

Epilepsia, 55(6), 787-90

View on PubMed ↗Publisher’s paper ↗

Citation

Cilio, Maria Roberta; Thiele, Elizabeth A; Devinsky, Orrin. (2014). The case for assessing cannabidiol in epilepsy.. Epilepsia, 55(6), 787-90. https://doi.org/10.1111/epi.12635