>> this is difficult to watch, but it does raise this important point. the traditional drugs used to treat epilepsy can be more dangerous than cannabis. vivian's doctor. >> i think one of the reasons marijuana is probably safe is it's related to the cannabidiol receptors. if you have too much stimulation or inhibition of them, they don't shut off breathing or respiration. >> and that's key. the current potent epilepsy drugs impact many parts of the brain, including the brain stem. they can essentially shut off the body's vital functions if you take too much. marijuana does not do that. and that's why it's virtually unheard of to have a marijuana overdose. it's one of the reasons so many doctors are starting to change their minds on cannabis. but we are talking about children, young children. and that's going to understandably raise concerns.