The number of current crack cocaine users in the U.S. in 2002 was about 567,000.
Irreversible physical side effects due to inhalant abuse can include bone marrow damage when gasoline is used for "huffing'.
Vicodin overdose is an extremely common occurrence, as individuals who abuse the drug can sometimes take more of the drug than their body can sufficiently process.
Tolerance to magic mushrooms may occur, especially when they are ingested continuously over a short period of time.