Recent research into the use of psilocybin to treat mental diseases, such as chronic depression and anxiety, has shown very promising and positive results. Small doses of psilocybin were given to a group of people who were terminally ill; another group was given a placebo. The group given the psilocybin registered to have much lower levels of anxiety and depression, while the placebo group had little to no effects. In contrast with current conventional antidepressants, the psilocybin treatments' positive effects were shown to last for weeks or even months. If you'd like to read more, here are some references:
http://archpsyc.jamanetwork.com/article.aspx?articleid=210962
www.nytimes.com/2012/04/22/magazine/how-psychedelic-drugs-can-help-patie...