“Evidence from high-quality randomized controlled trials (RCTs) suggests that cannabidiol probably reduces seizures among children with drug-resistant epilepsy (moderate certainty).”

https://www.ncbi.nlm.nih.gov/pubmed/30515765 

https://onlinelibrary.wiley.com/doi/abs/10.1111/epi.14608

“Phytocannabinoids produce anticonvulsant effects through the endocannabinoid system, with few adverse effects.” https://www.ncbi.nlm.nih.gov/pubmed/25475762