The other problem with lumping marijuana into these categories is that unlike most of them, marijuana is not chemically addictive. Drugs like cocaine and methamphetamine cause a chemical change in the brain which causes a chemical addiction in addition to a physical addiction. Though many will try to tell you that it is chemically addictive, they are really mistaking physical addiction for chemical addiction. If it makes you feel good, you want to keep feeling that way so you keep doing the drug. Chemical addiction includes severe withdrawal symptoms with abrupt discontinuation of the drug. While there are some withdrawal symptoms associated with it's use, they are usually restricted to people who smoke a lot for a long time, and the symptoms are not medically dangerous. If a cocaine addict were to stop abruptly, that person risks death from withdrawal symptoms if not properly taken care of. A more practical explanation would be: you don't see very many people lose their job, house, family, and belongings because of pot, but that situation is frequent among cocaine or meth addicts. The other complication of marijuana is that there is a legitimate medical use for it, while cocaine, meth, ecstasy, and alcohol have no medical use. Just in case someone tries to argue this, cocaine and heroin used to be used in hospitals about a century ago, but are no longer used because the health risks of their use far outweigh the benefits.