A marijuana-based drug has shown promising results as a treatment for a rare and deadly form of epilepsy in its first large-scale clinical trial. In a randomized trial of the cannabis derivative cannabidiol, scientists showed a significant reduction in seizures among children suffering from Dravet syndrome—a complex disease that leads to developmental problems and has high mortality rates. One hundred and twenty children aged between two and 18 were treated with either CBD or a placebo for 14 weeks. Researchers looked at the frequency of seizures over the 14 weeks and compared it with the baseline recorded for four weeks before the start of the trial. Their results showed the CBD group saw a 39 percent reduction in seizures over the course of the trial. Researchers also found 43 percent of the CBD group had at least 50 percent fewer seizures, while five percent became seizure free.