“Background: Autism spectrum disorder (ASD) is a heterogeneous neurodevelopmental condition often associated with severe behavioral disturbances and limited pharmacological treatment options. Cannabidiol (CBD) has emerged as a potential therapeutic option; however, evidence on its long-term effectiveness and safety in children with ASD is scarce.

Objective: To evaluate the long-term effectiveness and safety of purified CBD as addon therapy in children with severe ASD and treatment-resistant behavioral symptoms.

Material and methods: We conducted a prospective observational before-and-after study in children and adolescents (3-18 years) with ASD severity levels 2 or 3 and intellectual disability treated with add-on CBD. The primary outcome was change in caregiver-identified symptoms, while secondary outcomes included standardized behavioral scales (Repetitive Behavior Scale-Revised [RBS-R], Vineland Adaptive Behavior Scales-II maladaptive behavior domain, Aberrant Behavior Checklist [ABC], Pediatric Sleep Clinical Global Impressions-Severity, Autism Family Experience Questionnaire, and Parental Stress Scale). Safety and tolerability were assessed through caregiver-reported adverse events.

Results: Twenty children were enrolled, of whom 13 completed the long-term follow-up (mean 27.6 ± 1.3 months). Of the caregiver-identified symptoms, improvements observed during the initial short-term study were maintained or further improved during follow-up. Standardized scales showed modest but sustained improvements, particularly in irritability, social withdrawal, and hyperactivity. Mild, transient adverse events, mainly irritability or decreased appetite, did not recur during long-term followup, and concomitant medications were reduced in 40% of patients.

Conclusion: Long-term treatment with purified CBD in children with severe ASD was well tolerated and associated with sustained improvement in caregiver-reported outcomes and standardized scales.”

https://pubmed.ncbi.nlm.nih.gov/42248366

“Cannabidiol (CBD), a non-psychoactive cannabinoid, has gained increasing interest as a potential therapeutic option for both core symptoms of ASD and associated comorbidities, based on its anxiolytic, anti-inflammatory, and neuromodulatory properties, together with a generally favorable safety profile.”

“In this long-term follow-up of children with severe ASD treated with purified CBD, no significant differences were observed between the three-month and the 26-month evaluations, suggesting that the initial improvements were maintained over time. Among patients who completed the extended follow-up, purified CBD was well tolerated and associated with sustained improvement in several symptoms, particularly those identified by families as most disruptive in daily life.”

https://www.sciencedirect.com/science/article/abs/pii/S0091305726000754?via%3Dihub