Pilot trial found CBD was feasible and well-tolerated for behavioral problems in children with intellectual disability
A pilot randomized controlled trial of CBD (up to 20 mg/kg/day) in eight children with intellectual disability and severe behavioral problems found 100% completion, no serious adverse events, and a signal of efficacy favoring CBD over placebo.
Quick Facts
What This Study Found
All eight randomized children completed the full 8-week protocol. Protocol adherence was excellent: 100% for visits and medication, 92% for blood tests, 88% for questionnaires. No serious adverse events or dropouts occurred. All parents said they would recommend the study to other families. There was an efficacy signal favoring CBD over placebo.
Key Numbers
8 children randomized; 100% visit completion; 100% medication adherence; 92% blood test completion; 88% questionnaire completion; 0 serious adverse events; 0 dropouts; CBD dose up to 20 mg/kg/day (max 500 mg twice daily)
How They Did This
Double-blind, placebo-controlled, parallel-design pilot RCT of 98% CBD oil (Tilray) in children aged 8-16 with intellectual disability and severe behavioral problems. CBD was titrated over 9 days to 20 mg/kg/day (max 500 mg twice daily) for 8 weeks. Feasibility, acceptability, safety, and preliminary efficacy were assessed.
Why This Research Matters
Children with intellectual disability and severe behavioral problems have few effective treatment options, and existing medications carry significant side effect risks. This pilot demonstrates that a full-scale CBD trial is feasible in this population.
The Bigger Picture
This is one of the first placebo-controlled trials of CBD specifically for behavioral problems in children with intellectual disability. The excellent adherence and safety profile clear the way for larger efficacy trials.
What This Study Doesn't Tell Us
Very small sample (8 children) designed as feasibility pilot, not powered for efficacy. Short duration (8 weeks). Single-center study. The efficacy signal needs confirmation in a larger trial.
Questions This Raises
- ?What is the optimal CBD dose for behavioral problems in this population?
- ?Would longer treatment duration show sustained or increased benefit?
- ?Which behavioral domains respond most to CBD?
Trust & Context
- Key Stat:
- 100% completion rate with 0 serious adverse events
- Evidence Grade:
- Well-designed pilot RCT demonstrating feasibility, but far too small (n=8) to draw efficacy conclusions.
- Study Age:
- Published in 2021.
- Original Title:
- A pilot randomised placebo-controlled trial of cannabidiol to reduce severe behavioural problems in children and adolescents with intellectual disability.
- Published In:
- British journal of clinical pharmacology, 87(2), 436-446 (2021)
- Authors:
- Efron, Daryl(6), Freeman, Jeremy L, Cranswick, Noel(3), Payne, Jonathan M, Mulraney, Melissa, Prakash, Chidambaram, Lee, Katherine J, Taylor, Kaitlyn, Williams, Katrina
- Database ID:
- RTHC-03114
Evidence Hierarchy
Participants are randomly assigned to treatment or placebo groups to test cause and effect.
What do these levels mean? →Frequently Asked Questions
Was CBD safe for these children?
Yes. No serious adverse events occurred during the 8-week trial. The CBD dose was titrated up to 20 mg/kg/day, and all children completed the full protocol without discontinuation.
Did CBD improve behavior?
There was a signal of efficacy favoring CBD over placebo, but with only 8 participants, the study was designed to test feasibility rather than prove effectiveness. A larger trial is needed to confirm whether CBD meaningfully improves severe behavioral problems.
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Cite This Study
https://rethinkthc.com/research/RTHC-03114APA
Efron, Daryl; Freeman, Jeremy L; Cranswick, Noel; Payne, Jonathan M; Mulraney, Melissa; Prakash, Chidambaram; Lee, Katherine J; Taylor, Kaitlyn; Williams, Katrina. (2021). A pilot randomised placebo-controlled trial of cannabidiol to reduce severe behavioural problems in children and adolescents with intellectual disability.. British journal of clinical pharmacology, 87(2), 436-446. https://doi.org/10.1111/bcp.14399
MLA
Efron, Daryl, et al. "A pilot randomised placebo-controlled trial of cannabidiol to reduce severe behavioural problems in children and adolescents with intellectual disability.." British journal of clinical pharmacology, 2021. https://doi.org/10.1111/bcp.14399
RethinkTHC
RethinkTHC Research Database. "A pilot randomised placebo-controlled trial of cannabidiol t..." RTHC-03114. Retrieved from https://rethinkthc.com/research/efron-2021-a-pilot-randomised-placebocontrolled
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.