likewise marijuana or t.h.c., affects numerous places in this pathway and because they have more, the effects are more long lasting. it can last after getting high, there can be four days of cognitive impairment. so it suggests that, you know, what's going to happen on that test on thursday when you've had a busy weekend? these are things these kids need to know. >> so how much more alcohol and/or marijuana is there today among teenagers? >> actually, there's a lot. there is n.i.h. data, c.d.c. data telling us it is still a very big problem. especially in the mid teen years. actually, some of these other drugs, though, are possibly beginning to look like they're eclipsing alcohol. cigarettes are coming down because that's kind of not as big an issue as it had been though it's still an issue. but these are very real problems. now, the point is that kids can get access to these agents a lot easier now than even five or ten years ago through social networking. so it is a real issue to discuss with them. of course as some of these drugs like pot get legalized and of course alcohol is lega