Retrospective Observations from a Pilot Study on the Feasibility and Safety of Medication Reduction or Withdrawal in Children with Autism Spectrum Disorder Taking Cannabidiol-Rich Oil

Background: Due to the limited efficacy ofcurrent treatments for Autism Spectrum Disorder (ASD), a high proportion of families turn to alternative or unregulated interventions, including medicinal Cannabis-derived products. Interest has grown in exploring the potential of cannabidiol (CBD)-based preparations as adjunctive or alternative treatments for managing core and associated symptoms of ASD. Purpose: To explore whether a CBD-rich oil provided by a Brazilian civil association for therapeutic cannabis access might be used safely alone or as adjunct, and could allow for the reduction of other medications in children with ASD. Study design: Retrospective analysis of an open-label pilot study. Methods: Thirty children with ASD aged 2–15 years old were enrolled. The feasibility, safety, and preliminary effects of medication reduction or withdrawal alongside a 24-week administration of a CBD-rich oil (CBD: delta-9-tetrahydrocannabinol -THC- ratio 14.5:1) was assessed. Results: Twenty-seven participants completed the study. Sixteen participants reduced or withdrew medications under supervision; fourteen remained on or off medication. Mild side effects like increased appetite and nervousness occurred without clear differences between groups. Two participants with epilepsy experienced seizure recurrence following the tapering of valproic acid and risperidone, respectively. Exploratory observations suggested potential improvements in ASD symptoms, parenting stress, and neuropsychiatric evaluations across participants. Conclusions: The use of CBD-rich oil alongside supervised medication tapering maybe tolerated in some children with ASD. However, the study is limited by the retrospective design, small sample size, and lack of a placebo control. Careful clinical monitoring remains essential, particularly in children with epilepsy. Further randomized controlled trials are needed to investigate potential therapeutic roles, optimal dosing strategies, and long-term safety of CBD as an adjunctive or alternative treatment in ASD.