OPN1MW and Lennox-Gastaut syndrome: Two multicenter double-blind placebo-controlled trials investigated the short-term effect of CBD in LGS patients: the first one looked at the efficacy of CBD (20 mg/kg/day) as an add-on therapy for drop seizures in 171 patients (2–55 years) with treatment-resistant LGS and found a statistically significant reduction in drop seizure number in the CBD compared to the placebo group.42 The second study compared two doses (20 mg/kg/day and 10 mg/kg/day) of purified CBD to placebo and demonstrated a significant reduction in drop seizures versus placebo with both dosages.43