CBD Showed Mixed Results for Adults with Dravet Syndrome

In 18 adults with genetically confirmed Dravet syndrome, CBD added to existing medications produced meaningful seizure reduction in about 18% of patients, but adverse effects were common and led to discontinuation in some.

Silvennoinen, Katri et al.·Seizure·2021·Preliminary EvidenceRetrospective Cohort
RTHC-03527Retrospective CohortPreliminary Evidence2021RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Retrospective Cohort
Evidence
Preliminary Evidence
Sample
N=18

What This Study Found

Among 17 evaluable adults with Dravet syndrome treated with CBD (up to 20 mg/kg), 3 (17.6%) achieved greater than 30% reduction in convulsive seizures (range 87.5-100%), while adverse effects occurred in all patients, with transaminitis in 52.9% and behavioral side effects leading to discontinuation in 16.7%.

Key Numbers

18 adults (7 female); median age 27.5 years; median follow-up 176 days; 17.6% had >30% seizure reduction; transaminitis in 52.9%; behavioral AEs led to discontinuation in 16.7%; 7/18 stopped for lack of effect; 8/18 continue treatment; 41.2% showed physician-rated improvement.

How They Did This

Retrospective real-world study of 18 adults with genetically confirmed Dravet syndrome who received CBD through the GW Pharma early access programme at two UK neurology centers, with median follow-up of 176 days.

Why This Research Matters

Most CBD epilepsy research focuses on children. This study provides rare data on CBD effectiveness in adults with Dravet syndrome, where outcomes appear more modest and side effects more common than in pediatric studies.

The Bigger Picture

The gap between the modest seizure reduction rates and the higher rates of perceived improvement by physicians and families suggests CBD may offer quality-of-life benefits beyond seizure frequency alone, though careful monitoring is essential.

What This Study Doesn't Tell Us

Small sample size; no control group; retrospective design; early access programme may attract patients with more severe disease; median follow-up under 6 months.

Questions This Raises

  • ?Why do adults with Dravet syndrome appear to respond less robustly to CBD than children?
  • ?Would longer treatment duration improve response rates?

Trust & Context

Key Stat:
17.6% of adult Dravet patients achieved meaningful seizure reduction with CBD
Evidence Grade:
Small retrospective real-world study without controls, providing preliminary evidence on CBD in adult Dravet syndrome.
Study Age:
Data from GW Pharma early access programme at two UK centers.
Original Title:
Two-center experience of cannabidiol use in adults with Dravet syndrome.
Published In:
Seizure, 91, 5-8 (2021)
Database ID:
RTHC-03527

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

Does CBD work for adults with Dravet syndrome?

In this small study, about 18% of adults achieved meaningful seizure reduction, and some became seizure-free. However, all patients experienced side effects, and nearly 40% discontinued treatment.

What side effects occurred?

The most common was elevated liver enzymes (transaminitis) in 52.9%. Behavioral side effects led to discontinuation in 16.7% of patients, including one who had been seizure-free.

Read More on RethinkTHC

Cite This Study

RTHC-03527·https://rethinkthc.com/research/RTHC-03527

APA

Silvennoinen, Katri; Ritter, Laura Mantoan; Nashef, Lina; Hudgell, Kirsty; Balestrini, Simona; Sisodiya, Sanjay M; Sidhu, Meneka K. (2021). Two-center experience of cannabidiol use in adults with Dravet syndrome.. Seizure, 91, 5-8. https://doi.org/10.1016/j.seizure.2021.05.014

MLA

Silvennoinen, Katri, et al. "Two-center experience of cannabidiol use in adults with Dravet syndrome.." Seizure, 2021. https://doi.org/10.1016/j.seizure.2021.05.014

RethinkTHC

RethinkTHC Research Database. "Two-center experience of cannabidiol use in adults with Drav..." RTHC-03527. Retrieved from https://rethinkthc.com/research/silvennoinen-2021-twocenter-experience-of-cannabidiol

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.