nightmares of his childhood hiding from the nazis. the marijuana, he says, took him out of the darkness. >> you're free. you fly. >> when you smoke? >> yeah. >> there are 19 other patients here. scientists at tel aviv university are now studying their progress. they call the results outstanding. including weight gain, improved mood, pain and tremor reduction. but i can tell you as a doctor it was my next stop that proved the most surprising. this is israeli's largest hospital, sheba medical center. he is using marijuana to help him with the pain and nausea from chemotherapy. >> filling up the spoon. so that's your medicine inside there. >> you want to take it out? >> and he's doing it inside the hospital. >> how are you feeling? >> relief.