Mushrooms which contain psilocybin are found naturally occurring all over the world. England, Mexico, Hawaii and Thailand all have indigenous strains. Because of this, the mushrooms are often picked by the users themselves. They are eaten raw, often having been dried.
The fact that psilocybe mushrooms grow naturally in fields often leads to confusion about their legal status but magic mushrooms were made illegal internationally to possess or sell by the UN Single Convention on Psychotropic Drugs in 1971, although they were de facto decriminalized in the UK until 2005.
Psilocybe Mushrooms have no legal medical usage in any countries; however, the Beckley Foundation has a number of clinical trials underway which seek to establish whether there is any therapeutic usage. Studies are underway in the use of psilocybin in treating addiction in treatment-resistant nicotine addicts, anxiety in terminal cancer patients, and whether it can help in the recall of remote autobiographical memories.
The effects of psilocybin mushrooms are somewhat similar to the effects of LSD. It is a potent hallucinogen, and can cause severe visual distortion, as well as euphoria, laughter, and an altered mental state. People have been using mushrooms in indigenous cultures such as Mexico as part of religious ceremonies for hundreds of years, and shamanic cultures believe that they can put one into closer contact with the divine natural world.
As a psychedelic drug, mushrooms should not be used by people who are at risk of a psychotic episode. They are not damaging to the body, although there is a risk of injury while intoxicated. Taking an overly large dose could result in confusion, anxiety, paranoia and disturbing hallucinations, similar to a nightmare. Another risk is someone misidentifying toxic field mushrooms as “magic mushrooms” and poisoning themselves.