Cannabidiol (Epidyolex®) for severe behavioral manifestations in patients with tuberous sclerosis complex, mucopolysaccharidosis type III and fragile X syndrome: protocol for a series of randomized, placebo-controlled N-of-1 trials.
Watch for future results from these N-of-1 RCTs testing whether CBD reduces severe irritability in TSC, MPS III or FXS.
01Research in Context
What this study did
Müller et al. (2024) wrote a plan for testing cannabidiol in children and adults with three rare genetic syndromes: tuberous sclerosis complex, MPS III, and fragile X.
Each person will get both CBD oil and placebo for set weeks in a random order. Neither families nor raters will know which is which.
The team will watch if irritability, tantrums, or self-injury drop during CBD blocks compared with placebo blocks.
What they found
This paper only shows the plan. No kids have swallowed the oil yet, so there are no scores to share.
The authors promise future data sheets once the N-of-1 trials finish.
How this fits with other research
Boudreau et al. (2015) already showed that naltrexone can calm irritability in autistic children. Müller’s team picks the same target—severe behavior—but tests a different drug.
Laposa et al. (2017) warn that parents often report big “gains” on rating scales even when nothing was given. The new CBD plan answers that worry by using blinded crossover phases and direct counts of behavior.
Wagner et al. (2011) mapped fragile X behavior patterns, so the CBD study can pick the right symptoms to watch.
Why it matters
If the upcoming CBD trials show clear drops in aggression or self-hit, BCBAs will have a new medical partner to pair with behavior plans. Until then, keep using your functional assessment and reinforcement tools, but stay alert for the 2025 data drop that could add CBD to the care menu for TSC, MPS III, and FXS.
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02At a glance
03Original abstract
Many rare genetic neurodevelopmental disorders (RGNDs) are characterized by intellectual disability (ID), severe cognitive and behavioral impairments, potentially diagnosed as a comorbid autism spectrum disorder or attention-deficit hyperactivity disorder. Quality of life is often impaired due to irritability, aggression and self-injurious behavior, generally refractory to standard therapies. There are indications from previous (case) studies and patient reporting that cannabidiol (CBD) may be an effective treatment for severe behavioral manifestations in RGNDs. However, clear evidence is lacking and interventional research is challenging due to the rarity as well as the heterogeneity within and between disease groups and interindividual differences in treatment response. Our objective is to examine the effectiveness of CBD on severe behavioral manifestations in three RGNDs, including Tuberous Sclerosis Complex (TSC), mucopolysaccharidosis type III (MPS III), and Fragile X syndrome (FXS), using an innovative trial design. We aim to conduct placebo-controlled, double-blind, block-randomized, multiple crossover N-of-1 studies with oral CBD (twice daily) in 30 patients (aged ≥ 6 years) with confirmed TSC, MPS III or FXS and severe behavioral manifestations. The treatment is oral CBD up to a maximum of 25 mg/kg/day, twice daily. The primary outcome measure is the subscale irritability of the Aberrant Behavior Checklist. Secondary outcome measures include (personalized) patient-reported outcome measures with regard to behavioral and psychiatric outcomes, disease-specific outcome measures, parental stress, seizure frequency, and adverse effects of CBD. Questionnaires will be completed and study medication will be taken at the participants’ natural setting. Individual treatment effects will be determined based on summary statistics. A mixed model analysis will be applied for analyzing the effectiveness of the intervention per disorder and across disorders combining data from the individual N-of-1 trials. These N-of-1 trials address an unmet medical need and will provide information on the effectiveness of CBD for severe behavioral manifestations in RGNDs, potentially generating generalizable knowledge at an individual-, disorder- and RGND population level. EudraCT: 2021-003250-23, registered 25 August 2022, https://www.clinicaltrialsregister.eu/ctr-search/trial/2021-003250-23/NL.
BMC Psychiatry, 2024 · doi:10.1186/s12888-023-05422-3