Cannabis CAN cause people with underlying mental disorders to have their illness triggered by cannabis, and it may not be temporary! Heavy use of cannabis and its derivatives has caused mental illness which was not temporary. Most people need not worry about this. Discored was right that most people, when they stop smoking, will lose any negative effects cannabis may have had on their mental state. A minority will, however, have problems that may not be temporary. No drug is harmless, and it is easy to underestimate the way cannabis, particularly skunks, can effect you. Many skunks are high in THC (has psychotic properties) but low in CBD (anti psychotic properties) so skunks may be more likely to cause paranoia and anxiety, particularly with less experienced users. By the way, the receptors cannabis can trigger are called cb1 and cb2. They aren't designed to be triggered by cannabis, but by anandamide. The fact that cannabinoids are almost identical to this substance naturally produced by the body is probably a fluke of nature. Opium has a similar effect. The opiate receptors weren't designed to be triggered by opium or opium derivatives (heroin, morphine etc). opium is like cannabis, almost identical to substances produced by the body naturally. Many people believe cannabis and opium were MEANT to be used by man, but this was before we understood about anandamide.
Hope this was useful.
AByrne
Senior Drugs Worker
West Mids.