The Beatles Fan, that's lies. In order to die from acid, a person would have to take 38,500 doses of it, which would cost a person $192,500. While it's true you can die from lsd (In an extremely high dose like that), your statement is an exaggeration because nobody has ever died from it since nobody has ever taken that much. The only people who die as a result of lsd are people that take it and then jump out of windows thinking they can fly.
As far as marijuana's effects on the brain, look at "Man's" link, that guy's answer in the link pretty much addresses that nonsense.
Too much propaganda, misinformation, and lies in the world when it comes to illegal substances. The public has been lied to and the public continues to repeat those lies and spread them around.