One year of CBD treatment did not harm cognitive function in children with treatment-resistant epilepsy

Children and teenagers with treatment-resistant epilepsy showed no cognitive decline after one year of add-on CBD therapy, with a nonsignificant trend toward improvement in some areas.

Thompson, Matthew D et al.·Epilepsy & behavior : E&B·2020·Moderate EvidenceObservational
RTHC-02879ObservationalModerate Evidence2020RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Observational
Evidence
Moderate Evidence
Sample
N=38

What This Study Found

Among 38 pediatric patients (ages 3-19) with treatment-resistant epilepsy, those who completed cognitive testing showed no significant changes after one year of CBD. There was a nonsignificant trend toward improvement in some cognitive domains. Adaptive behavior scores also remained stable.

Key Numbers

38 participants ages 3-19. 24 were unable to complete cognitive testing due to severity of impairment. Among those tested, no statistically significant cognitive changes. Adaptive behavior scores unchanged after one year.

How They Did This

Open-label prospective study of 38 participants with treatment-resistant epilepsy receiving pharmaceutical CBD (Epidiolex) as add-on treatment. Cognition assessed with NIH Toolbox Cognition Battery at baseline and one year. For cognitively impaired participants unable to complete testing, caregivers completed the ABAS-II.

Why This Research Matters

Parents and clinicians worry about cognitive side effects of adding another medication, especially for children already on multiple anticonvulsants. This study provides reassurance that CBD does not appear to worsen cognition over one year.

The Bigger Picture

As CBD becomes an established add-on treatment for severe epilepsy, long-term safety data on cognition are essential. This study adds to the evidence that CBD is cognitively safe in the pediatric population most likely to receive it.

What This Study Doesn't Tell Us

Open-label design without a control group. Small sample with high attrition (24 of 38 could not complete cognitive testing). Practice effects from repeated testing could mask subtle declines.

Questions This Raises

  • ?Would longer follow-up reveal any cognitive effects?
  • ?Could CBD actually improve cognition in some patients by reducing seizure burden?
  • ?Would results differ with higher or lower CBD doses?

Trust & Context

Key Stat:
No significant cognitive decline after 1 year of CBD in pediatric epilepsy
Evidence Grade:
Prospective study with validated cognitive measures, but small open-label sample without a control group.
Study Age:
2020 study. Part of ongoing safety monitoring for pharmaceutical CBD (Epidiolex) in pediatric epilepsy.
Original Title:
Cognitive function and adaptive skills after a one-year trial of cannabidiol (CBD) in a pediatric sample with treatment-resistant epilepsy.
Published In:
Epilepsy & behavior : E&B, 111, 107299 (2020)
Database ID:
RTHC-02879

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / ObservationalSnapshot without intervening
This study
Case Report / Animal Study

Watches what happens naturally without intervening.

What do these levels mean? →

Frequently Asked Questions

Did CBD improve cognition in these children?

There was a nonsignificant trend toward improvement in some cognitive domains, but the study was not designed or powered to detect cognitive improvements.

Why could so many participants not complete cognitive testing?

24 of 38 participants had cognitive impairment too severe to complete standardized testing. This is common in treatment-resistant epilepsy populations, where seizures and multiple medications can significantly affect cognitive function.

Read More on RethinkTHC

Cite This Study

RTHC-02879·https://rethinkthc.com/research/RTHC-02879

APA

Thompson, Matthew D; Martin, Roy C; Grayson, Leslie P; Ampah, Steve B; Cutter, Gary; Szaflarski, Jerzy P; Bebin, E Martina. (2020). Cognitive function and adaptive skills after a one-year trial of cannabidiol (CBD) in a pediatric sample with treatment-resistant epilepsy.. Epilepsy & behavior : E&B, 111, 107299. https://doi.org/10.1016/j.yebeh.2020.107299

MLA

Thompson, Matthew D, et al. "Cognitive function and adaptive skills after a one-year trial of cannabidiol (CBD) in a pediatric sample with treatment-resistant epilepsy.." Epilepsy & behavior : E&B, 2020. https://doi.org/10.1016/j.yebeh.2020.107299

RethinkTHC

RethinkTHC Research Database. "Cognitive function and adaptive skills after a one-year tria..." RTHC-02879. Retrieved from https://rethinkthc.com/research/thompson-2020-cognitive-function-and-adaptive

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.