NEW YORK， Dec. 2 (Xinhua) -- The psychedelic substance found in the hallucinogenic "magic mushrooms" can effectively treat anxiety and depression in cancer patients， U.S. researchers have found.


In two separate studies， which covered 80 cancer patients， about 80 percent of the subjects showed clinically significant reductions in psychological disorders after a single dose of psilocybin， an ingredient found in the certain mushrooms.


In both trials， the intensity of the mystical experience described by the patients after taking the drugs correlated with the degree to which their depression and anxiety decreased. Their response sustained some seven month with minimum side effects.


The approach "significantly lessens mental anguish in distressed cancer patients for months at a time，" said the findings of the two studies， published Thursday concurrently in The Journal of Psychopharmacology.


"Cancer patients with anxiety and depression need help immediately， especially if you consider that they are at elevated risk for completed suicide，" said Stephen Ross， leader of one study.


Psilocybin is illegal in the U.S. and many other countries. Studies on its medical use had looked promising in the 1940s and 1950s， yet they stopped in the early 1970s after a regulatory crackdown on the drugs due to their wide use for recreational purposes.


Research has resumed since about 2000， mostly from private funding. However， researchers have warned against anyone trying psychedelic drugs on their own， which could be risky.