Researchers at the Center for Medicinal Cannabis Research at University of California San Diego School of Medicine have found that cannabidiol (CBD), a non-intoxicating compound found in cannabis, could help reduce problematic behaviors in autistic boys. The results provide valuable insights into the potential benefits and limitations of CBD as a therapeutic intervention for autism.
Autism spectrum disorder is a complex neurodevelopmental condition characterized by social communication difficulties, repetitive behaviors and restricted interests. In more severe cases, these behaviors can also include self-injury or aggression. While existing treatments can help manage these symptoms, there is a pressing need for effective and safe interventions to address the diverse needs of autistic individuals.
Some prior studies have suggested that CBD could help reduce problematic behaviors in children with autism. However, no controlled clinical trials have addressed safety, tolerability and efficacy of this treatment approach until now.
In the trial, autistic boys with severe behavior problems aged 7–14 years were split into two groups. One received eight weeks of daily CBD then eight weeks of placebo, separated by a four-week “washout” period in which no treatment was given. The other group received placebo first, then CBD. Behavioral assessments were completed before and after each treatment phase. A total of 30 participants completed the trial.
The researchers found:
- CBD was safe and well-tolerated in boys with severe autism and behavioral problems – participants were able to take the drug without difficulty and there were no serious adverse events.
- While no significant differences were found between CBD and placebo on broad measures of behavior, clinician impressions suggested that approximately two-thirds of participants showed evidence of clinical improvement with CBD.
- Reductions in aggressive behaviors and hyperactivity were observed most frequently by clinicians, with improvements in communication seen in almost 30% of participants.
- While both groups showed improvements during the study, demonstrating a strong placebo effect, the CBD group generally showed greater improvement than the placebo group.
The study’s findings suggest that while CBD may have some benefits in reducing problematic behaviors in autistic children, its effectiveness is not universally established, and more research is needed to fully understand its therapeutic potential. The study’s results also underscore the importance of rigorous, controlled trials in evaluating the efficacy of novel treatments for autism.
The study, published in the Journal of Autism and Developmental Disorders, was led by UC San Diego School of Medicine distinguished professors Doris Trauner, M.D., in the Departments of Neurosciences and Pediatrics, and Igor Grant, M.D., in the Department of Psychiatry.
Source:
Journal reference:
Trauner, D., et al. (2025). Cannabidiol (CBD) Treatment for Severe Problem Behaviors in Autistic Boys: A Randomized Clinical Trial. Journal of Autism and Developmental Disorders. doi.org/10.1007/s10803-025-06884-y.