Cannabis extract shows efficacy in treatment of autism

The use of cannabidiol (CBD) cannabis extract shows efficacy in the treatment of autism spectrum disorder (ASD) in children and adolescents, researchers report.

The findings from a new meta-analysis of relevant data were reported on April 8, 2025 at the annual meeting of  European Congress of Psychiatry

Lead investigator Dr. Lara Cappelletti Beneti Branco from São Camilo University Center, University of São Paulo in Brazil said, “The global population prevalence of ASD diagnosis amongst children and adolescents is growing, but many treatment pathways are not effective. It is promising to see the effect of CBD cannabis extract on the study participants. However, there still needs to be considerable focus on further research with larger trials to clarify its efficacy and safety in managing ASD.”

The objective of the new study was to review and meta-analyze the evidence from randomized, placebo-controlled clinical trials investigating the efficacy and safety of CBD cannabis extracts in alleviating symptoms of ASD in children and adolescents.

The investigators conducted a comprehensive online search for relevant studies. The search was updated on September 8, 2024.

They found 3 eligible studies in which 276 subjects had been enrolled (78.3% male; mean age 10.5 years, range 5 to 21).

The dosage of CBD cannabis extract started at 1 mg/kg per day and was titrated up to 10 mg/kg.

They reported that, compared to placebo, treatment with CBD cannabis extracts statistically significantly enhanced social responsiveness (p < 0.01).

The same treatment also reduced disruptive behavior (p = 0.02) and alleviated anxiety (p = 0.03.)

And CBD cannabis extracts also improved sleep quality, without reaching statistical significance.

There was no significant difference in adverse effects between the CBD extracts treatments and placebo

The authors concluded, “CBD cannabis extracts appear to provide meaningful benefits for children and adolescents with ASD, showing moderate improvements in social responsiveness and small yet notable reductions in disruptive behaviors and anxiety. They do not seem to significantly increase adverse effects compared to placebo, suggesting a favorable safety profile. These findings support the potential consideration of CBD cannabis extracts in ASD treatment plans. However, the review’s limitations include a small number of studies, limited sample sizes, and significant heterogeneity. Future research with larger, robust trials is needed to clarify the efficacy and safety of CBD cannabis extracts in managing ASD.”

Professor Geert Dom, president of the European Congress of Psychiatry, “ASD can be extremely frustrating for all involved; parents of children and adolescents with the disorder, the treating clinicians and of course the children and adolescents themselves. A large part of this frustration is down to finding a viable treatment option that works to reduce symptoms. It is with delight that we see the results of this meta-analysis and we hope to see further research into this so we can move towards a solution to the unmet need within this community”.