I've been to a lot of parties, where speed, hallucinogens, and other drugs have been used in front of me. It all depends on the maker of the artificial drug. A person on; for example: amphetamines, and PcP have the ability to fatigue less, but the increased heart rate is enough to cause a cardiovascular problem which can eventually lead to heart failure if the body is over worked. Pcp is more of a hallucinogenic drug, but high doses of it, can render the nervous system to be harmless. I've never tried Pcp, nor will I have the guts to try it, but I have tried amphetamines once, and that shit makes you hyper, it's a dangerous caffine trip experience that was quite interesting.
I still think everyone should just smoke weed, and let the government legalize that. Then everyone would be too stoned to try any other drugs, and when the cops try to arrest you, you're too busy laughing at them, because you thought that one of the officers looked like Don Knotts, and you kept calling him Barney. :P