The specific goals of this phase I dose finding study conducted in consecutively enrolled patients 1-18 years of age are to prospectively and longitudinally assess the safety and tolerability, including cognitive effects, of CBD at various doses between 5 mg/kg/day and 25 mg/kg/day with additional titration in some subjects up to 50 mg/kg/day. In order to participate in the study, participants will need to fulfill the inclusion and exclusion criteria.