What is established
The FDA-approved cannabidiol medicine Epidiolex is indicated for seizures associated with Lennox-Gastaut syndrome, Dravet syndrome, and tuberous sclerosis complex in patients one year of age and older. The evidence comes from a standardized prescription formulation studied in controlled trials.
This does not mean retail CBD is interchangeable. Concentration, purity, absorption, labeling accuracy, and clinical monitoring can differ substantially.
The safety evidence matters too
The current prescribing information warns about liver injury, sedation, suicidal thoughts or behavior associated with antiepileptic drugs, hypersensitivity, and interactions. Liver testing and medication review are part of supervised treatment.
Suddenly stopping an antiseizure medicine can worsen seizures or precipitate status epilepticus. Treatment changes require the prescribing clinician.
What remains uncertain
Evidence for these named syndromes should not be generalized to every epilepsy type or to cannabis products containing THC. Research continues, but the condition, formulation, outcome, and adverse effects must remain attached to any conclusion.