The Evolving Role of Cannabidiol-Rich Cannabis in People with Autism Spectrum Disorder: A Systematic Review

Autism spectrum disorder (ASD) is a neurological disease and lifelong condition. The treatment gap in ASD has led to growing interest in alternative therapies, particularly in phytocannabinoids, which are naturally present in Cannabis sativa. Studies indicate that treatment with cannabidiol (CBD)-rich cannabis may possess the potential to improve fundamental ASD symptoms as well as comorbid symptoms. This systematic review aims to assess the safety and efficacy of CBD-rich cannabis in alleviating the symptoms of ASD in both children and adults, addressing the treatment gap and growing interest in CBD as an alternative treatment. A comprehensive literature search was conducted in February 2024 using the PUBMED and Scopus databases while following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The search focused on studies from 2020 onward involving human populations diagnosed with ASD and treated with CBD. Four studies met the inclusion criteria and were analyzed. The review included 353 participants with ASD from studies conducted in Israel, Turkey, and Brazil. The studies varied in design, sample size, dose, and treatment duration. Dosages of CBD were often combined with trace amounts of THC. Improvements were noted in behavioral symptoms, social responsiveness, and communication, but cognitive benefits were less consistent. Adverse effects ranged in severity. Mild effects such as somnolence and decreased appetite were common, while more concerning effects, including increased aggression, led to some cases of treatment discontinuation. CBD-rich cannabis shows promise in improving behavioral symptoms associated with ASD. However, variations in study designs, dosages, and outcome measures highlight the need for standardized assessment tools and further research to understand pharmacological interactions and optimize treatment protocols. Despite the mild adverse effects observed, larger, well-controlled trials are necessary to establish comprehensive safety and efficacy profiles.