Withdrawal symptoms can vary significantly among individuals, but some symptoms such as depression, anxiety and craving are very common under most circumstances.
PCP is often added is to as LSD or methamphetamine, and sometimes users are unaware of this and may take a lethal dose.
The number of emergency room visits involving nonmedical use of pharmaceuticals has increased 98.4 percent between 2004 and 2009, from 627,291 visits to 1,244,679.
Studies indicate that Asian-American adolescent girls in the U.S. are the least likely use marijuana.