A systematic review of 42 studies found purified CBD effective across a broad range of epilepsy types beyond Dravet and Lennox-Gastaut syndromes, including CDKL5 deficiency, Dup15q, Doose, and other rare syndromes.
Pediatric neurologists, families of children with rare epilepsy syndromes, and regulatory bodies considering expanded CBD indications.
CBD showed promise across 6+ epilepsy syndromes beyond its 3 approved indications
What the researchers found
Beyond its approved indications (DS, LGS, TSC), purified CBD showed effectiveness in open-label studies for CDKL5 deficiency disorder, Aicardi syndrome, Dup15q syndrome, Doose syndrome, SYNGAP1 encephalopathy, and epilepsy with myoclonic absences. A randomized controlled trial in tuberous sclerosis complex showed significantly greater seizure reduction than placebo. Common adverse events: somnolence, decreased appetite, diarrhea, elevated liver enzymes.
Why it matters
Many children with rare epilepsy syndromes have no effective treatment options. This review provides preliminary evidence that purified CBD may help across a wider range of epilepsy types than currently approved, potentially expanding access for thousands of patients.
The numbers in context
570 records screened, 42 included. CBD doses up to 50 mg/kg/day. Effective for: DS, LGS, TSC (approved), plus CDKL5, Aicardi, Dup15q, Doose, SYNGAP1, myoclonic absences (preliminary). RCT in TSC: significant seizure reduction vs. placebo.
How the study worked
Systematic review of MEDLINE and NIH Clinical Trials Registry (no date or language restrictions). 570 records screened, 42 studies included. Included clinical trials, cohorts, case-control, cross-sectional, case series, and case reports of pharmaceutical-grade CBD (>98% purity) in sesame oil oral solution.
What this study cannot tell us
Most evidence beyond DS/LGS/TSC comes from open-label studies. No controlled trials for the rarer syndromes. Publication bias likely. Cannot determine optimal dosing for each syndrome.
How to read the evidence
Comprehensive systematic review but most evidence for newer indications comes from uncontrolled studies.
When this study was published
2021 systematic review with no date restrictions.
The bigger picture
The FDA has approved CBD for three epilepsy syndromes, but this review suggests the mechanism of action may be relevant to epilepsy broadly. If confirmed in controlled trials, purified CBD could become a treatment option for many currently untreatable seizure disorders.
Questions still open
- Which additional epilepsy syndromes should be prioritized for CBD clinical trials? Is there a common mechanism explaining CBD efficacy across different epilepsy types? Would insurance cover off-label CBD use based on this evidence?
Common questions
Which epilepsy types does CBD help with?
Is this about any CBD product?
Read the original research
Highly Purified Cannabidiol for Epilepsy Treatment: A Systematic Review of Epileptic Conditions Beyond Dravet Syndrome and Lennox-Gastaut Syndrome.
CNS drugs, 35(3), 265-281
Citation
Lattanzi, Simona; Trinka, Eugen; Striano, Pasquale; Rocchi, Chiara; Salvemini, Sergio; Silvestrini, Mauro; Brigo, Francesco. (2021). Highly Purified Cannabidiol for Epilepsy Treatment: A Systematic Review of Epileptic Conditions Beyond Dravet Syndrome and Lennox-Gastaut Syndrome.. CNS drugs, 35(3), 265-281. https://doi.org/10.1007/s40263-021-00807-y
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