"After years of anecdotal claims about its benefits the cannabis derivative cannabidiol reduced seizure frequency by  percent for patients with Dravet syndrome  a rare severe form of epilepsy  in the first largescale randomized clinical trial for the compound. The findings were published online May  in the New England Journal of Medicine http Cannabidiol should not be viewed as a panacea for epilepsy but for patients with especially severe forms who have not responded to numerous medications these results provide hope that we may soon have another treatment option says lead investigator Orrin Devinsky MD httpnyulangone.orgdoctorsorrindevinsky professor of neurology neurosurgery and psychiatry and director of the Comprehensive Epilepsy Center httpnyulangone.orglocationscomprehensiveepilepsycenter at NYU Langone Medical Center. We still need more research but this new trial provides more evidence than we have ever had of cannabidiols effectiveness as a medication for treatmentresistant epilepsy.  Cannabidiol or CBD is a compound in the cannabis plant that does not contain psychoactive properties that induce a high. The study included a liquid pharmaceutical formulation of CBD called Epidiolex which is manufactured by GW Pharmaceuticals and has not been approved by the U.S. Food and Drug Administration. GW Pharmaceuticals funded the clinical trial.   For the study  children and adolescents with Dravet Syndrome between the ages of  and  years were randomized across  sites in the United States and Europe to receive either CBD  mgkg or placebo added to their existing treatment over a week period. Seizure frequency was tracked for one month prior to the study for baseline readings and during the course of the study. Specifically seizure frequency dropped in the CBDtreated group by  percent from a median of nearly  convulsive seizures per month before the study to about six three patients seizures stopped entirely. In the placebo group there was a  percent reduction in seizures from about  monthly seizures to fourteen. The difference in the degree of seizure reduction between the CBD group and the placebo group was both statistically significant and clinically consistent.   Side effects  experienced by . percent of patients in the CBD group and . percent of those treated with placebo  were generally reported as mild or moderate in severity. The most common side effects in the CBD group were vomiting fatigue and fever. Eight participants from the CBD group withdrew from the trial due to side effects compared to one participant in the placebo group. The new study confirms results from a December  openlabel expanded access program led by Dr. Devinsky httpnyulangone.orgpressreleasesmarijuanaderivativereducesseizuresinchildrenyoungadultswithtreatmentresistantepilepsy that reported reductions in seizure frequency. In that program both the researchers and patients families knew they were receiving CBD which may have introduced a bias into the results. This new randomized controlled clinical study eliminated those concerns as participants and their physicians did not know if they were on CBD or placebo say the study authors. Future research will look at whether safety and tolerability might be improved and whether efficacy of CBD can be maintained at lower doses. Longer term studies of CBD for Dravet Syndrome as well as for other forms of treatmentresistant epilepsy are also underway. In addition to Dr. Devinsky the coauthors in this study were J. Helen Cross PhD FRCPCH Linda Laux MD Eric Marsh MD Ian Miller MD Rima Nabbout MD Ingrid E Scheffer MD PhD  Elizabeth Thiele MD and Stephen Wright MD  on behalf of The Cannabidiol in Dravet Syndrome Study Group. Judith Bluvstein MD httpnyulangone.orgdoctorsjudithbluvstein and Daniel Friedman MD httpnyulangone.orgdoctorsdanielfriedman also served as coauthors at the NYU Langone site involved in the study."