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Epilepsy research

Explore published research on epilepsy, including study methods and limitations.

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2016 / Pilot Study / Moderate evidence

The Trial That Made CBD a Medicine: From Desperate Parents to FDA Approval

The clinical program that turned CBD into the first FDA-approved cannabis-derived drug. Open-label trial: 214 patients, 36.5% seizure reduction. NEJM RCT: 120 Dravet patients, seizures dropped from 12.4 to 5.9/month vs placebo (p=0.01). Epidiolex approved June 2018.

2021 / Retrospective Cohort / Preliminary evidence

CBD Showed Mixed Results for Adults with Dravet Syndrome

Real-world study of 18 adults with Dravet syndrome found CBD reduced seizures by over 30% in 17.6%, but adverse effects were universal and led to discontinuation in some patients.

2025 / Retrospective Cohort / Moderate evidence

CBD for Epilepsy Types Beyond Its Approved Indications

Off-label CBD treatment across 108 patients with various refractory epilepsies achieved 38.9% responder rate at three months, with tolerability similar to approved indications.

2026 / Retrospective Analysis / Moderate evidence

CBD Helps Reduce Drug-Resistant Epileptic Spasms in Children

A study of 53 children found that CBD (Epidyolex) reduced drug-resistant epileptic spasms by ≥50% in nearly 60% of patients, with the best results in children with Down syndrome and cortical malformations.

2026 / Clinical Trial / Strong evidence

CBD May Not Have Anti-Seizure Properties On Its Own

A rigorous crossover trial found CBD had no effect on brain excitability or sedation at either low or high doses, suggesting its anti-epileptic benefits may come from drug interactions rather than direct activity.

2018 / Randomized Controlled Trial (Phase 3, Double Blind, Placebo Controlled) / Strong — Gold Standard RCT Design Published In The Lancet evidence

The Second Confirmation: CBD Works for Lennox-Gastaut Seizures Too

Phase 3 RCT in The Lancet: CBD reduced Lennox-Gastaut drop seizures by 43.9% vs 21.8% placebo (p=0.0135). The second RCT that led to Epidiolex becoming the first FDA-approved cannabis drug.

1980 / Double Blind, Placebo Controlled Clinical Trial (Two Phases: Safety + Efficacy) / Moderate — Gold Standard Design But Very Small Sample Size (N=15 For Efficacy) evidence

The CBD Epilepsy Discovery That Was Ignored for 40 Years

The first CBD epilepsy trial (1980): 10% of CBD patients still seizing vs 90% placebo. Published by Carlini and Mechoulam, ignored for 40 years, vindicated by Epidiolex trials in 2017-2018.

2018 / Randomized Controlled Trial (Dose Ranging, Double Blind, Class I Evidence) / Strong For Safety Characterization; Underpowered For Efficacy (N=34) evidence

The Dose-Ranging Study That Explained CBD's Side Effects

Small dose-ranging trial (34 Dravet patients, ages 4-10) that identified the CBD-clobazam interaction explaining somnolence, confirmed the CBD-valproate liver signal, and showed dose-proportional pharmacokinetics.