Results from a double-blind, placebo-controlled trial published in The New England Journal of Medicine revealed that children with Dravet syndrome, a severe form of epilepsy, had fewer seizures after taking a daily oral solution of the cannabis compound called cannabidiol, which does not have the psychoactive properties of marijuana. Over a 14-week treatment with cannabidiol, convulsive seizures dropped from a monthly average of 12.4 to 5.9. In comparison, seizures in the placebo group decreased from a monthly average of 14.9 to 14.1. During the study, seizures stopped completely in 5 percent of patients taking cannabidiol.

"Seizures in Dravet syndrome are extremely difficult to control and they can be deadly," says study co-author Linda Laux, MD, from Stanley Manne Children's Research Institute at Ann & Robert H. Lurie Children's Hospital of Chicago. "Our results are encouraging, especially considering that we don't have any antiepileptic drugs approved for Dravet syndrome in the U.S."

The study included 120 children and young adults with Dravet syndrome and drug-resistant seizures. They were randomly assigned to receive either cannabidiol or a placebo, in addition to standard antiepileptic treatment.

Adverse events were reported in 93 percent of the patients taking cannabidiol, compared to 75 percent of the patients in the placebo group. The most common side effects were drowsiness, diarrhea and decreased appetite.

"We will need more data to determine the long-term efficacy and safety of cannabidiol for Dravet syndrome," says Laux, who is the Medical Director of the Comprehensive Epilepsy Center at Lurie Children's and Assistant Professor of Pediatrics at Northwestern University Feinberg School of Medicine.