CNN Weed Dr. Sanjay Gupta Reports April 19, 2015 23:34:00
And it's perhaps one of the biggest reasons most people think pot is safe. in fact, a new study of children showed that by high school only one in five think marijuana is harmful. that's the lowest number in more than two decades, and it's something we heard over and over as we traveled around the country. >> not really that harmful. >> it has a lot of benefits. not really too concerned about it. >> i think it's safe if you're a safe person. >> but the experts we spoke to said there is more to the story. >> there are people who compulsively smoke, who want to stop smoking, but they can't stop ...