Psilocybin 395researchers ingested the drug together with state prison inmates to determine
whether the experiences would promote life changes motivating inmates to
stay out of prison upon release. Leary reported outstanding success, with psi-
locybin inmates committing far fewer repeat offenses sending them back to
prison. Subsequent investigation, however, revealed serious flaws in Leary’s
research; in reality the percentage of inmates returning to prison for new crime
was the same in the psilocybin group as in those who did not receive the
drug. Leary’s advocacy of widespread hallucinogenic drug use was based
partly upon flawed research.
A case report notes successful use of psilocybin mushrooms to ease, though
not eliminate, compulsions and obsessions.
Drawbacks.Blood pressure rose in volunteers who received psilocybin; re-
action times slowed; hearing became more sensitive; and individuals often felt
cold. Dizziness, nausea, and vomiting can occur. Some persons feel nervous
and even fearful during a psilocybin experience. After a psilocybin session
people may feel worn out for several hours, maybe for more than a day.
Reliable information on mushroom effects is more challenging to obtain
than reliable information about psilocybin because mushrooms contain many
other chemicals, sometimes including illicit substances that have been added
without a user’s knowledge. And mushroom eaters may simultaneously use
other substances deliberately, further clouding knowledge of what the mush-
room itself is doing. With the mushrooms, burning or prickling sensations are
routine, as are perspiration, yawning, fatigue, slowed pulse rate, lowered
blood pressure and body temperature, and uneasiness. An overdose com-
monly brings on nausea, vomiting, high blood pressure, and abnormal heart-
beat. Heart attack has been reported but seems uncommon.
Abuse factors.An authority who searched scientific reports about 20 drugs
considered to have potential for dependence (includingheroin) found oral
psilocybin to have the least. Psilocybin,LSD, andmescalineall share some
cross-tolerance, meaning that they can be at least partially substituted for one
another.
Drug interactions.Alcoholmay cause a flashback of hallucinations up to a
week after using psilocybin.
Cancer.A laboratory test found that psilocybin lacked actions expected from
chemicals that cause cancer.
Pregnancy.Not enough scientific information to report.
Additional information.Some psilocybin mushroom species contain the
Schedule I controlled substance psilocyn (also called psilocin, CAS RN 520-
53-6). Mushrooms are not the only source of psilocyn; laboratories can man-
ufacture it artificially, and reportedly human body chemistry transforms
psilocybin into psilocyn. A case report notes someone who successfully used
psilocyn to reduce obsessions and compulsions. The chemical can reduce ap-
petite in dogs. Researchers report that tolerance develops in mice. Experimen-
tation with mice found no evidence that psilocyn causes birth defects.
Additional scientific information may be found in:
Doblin, R. “Dr. Leary’s Concord Prison Experiment: A 34-Year Follow-up Study.”Jour-
nal of Psychoactive Drugs30 (1998): 419–26.