THURSDAY, Sept. 29 (HealthDay News) -- In new research that will almost certainly create controversy, scientists working with the hallucinogen psilocybin -- the active ingredient found in "magic mushrooms" -- have found that a single dose of the drug prompted an enduring but positive personality change in almost 60 percent of patients.

Specifically, tests involving a small group of patients in a strictly controlled and monitored clinical setting revealed that, more often than not, one round of psilocybin exposure successfully boosted an individual's sense of "openness." What's more, the apparent shift in what is deemed to be a key aspect of personality did not dissipate after exposure, lasting at least a year and sometimes longer.

"Now this finding is really quite fascinating," said study author Roland R. Griffiths, a professor in the departments of psychiatry and neuroscience at Johns Hopkins University School of Medicine in Baltimore. "And that is because personality is considered a stable characteristic of the psychology of people. It's been thought to be relatively immutable, and stable across the lifespan.

"But, remarkably, this study shows that psilocybin actually changes one domain of personality that is strongly related to traits such as imagination, feeling, abstract ideas and aesthetics, and is considered a core construct underlying creativity in general," he added. "And the changes we see appear to be long-term."

Griffiths said it's possible psilocybin could have therapeutic uses. For example, he is currently studying whether the hallucinogen might be useful in helping cancer patients cope with the depression and anxiety that often accompany the disease, and whether it might help smokers quit the habit.

Griffiths and his colleagues discuss their findings, funded in part by the U.S. National Institute on Drug Abuse, in the new issue of the Journal of Psychopharmacology.

Working with 51 psychologically healthy volunteers, the study authors conducted baseline personality tests before engaging the participants in a total of two to five experiment sessions, each lasting about eight hours.

The researchers said that almost all of the study participants deemed themselves to be "spiritually active." Roughly half had completed a post-graduate education.

Not all the sessions involved psilocybin. In fact, the hallucinogen was administered to participants only once, at a dose described as "moderate to high," and the volunteers were never told which session actually entailed drug exposure.

A minimum break of three weeks was allotted between sessions.

During each session, participants were asked to lay down while wearing both eye masks and headphones (with music piped in) to screen out their external environment and focus on their interior experience.

The results: repeated personality and so-called "states of consciousness" testing revealed that some critical aspects of the participants' personalities remained unchanged. In the key domains of neuroticism, extroversion, agreeableness and conscientiousness, psilocybin appeared to register little to no impact.

The exception: "openness." Not only did openness increase significantly in response to high doses of the hallucinogen, it also remained at an elevated level throughout a 14-month follow-up period.

"Certainly we want to underscore do not try this at home," Griffiths cautioned. "Because clearly there are several kinds of potential downsides. One is that personality changes are personality changes. Now, we don't have any reason to think that the changes we see are toxic in any way. It appears to be a change that people value in a positive way. But certainly more research needs to be done.

"And the other note," he added, "is that we've conducted our research under conditions where we've screened out people who are potentially vulnerable to adverse effects. And we've given the drug in a hospital setting with two people at their side throughout, so there's virtually no opportunity for the patient to do something dangerous. But we know that, shockingly, all the time people who use mushrooms recreationally sometimes end up getting into accidents or engage in homicidal behavior or suicide.

"So we certainly don't want to imply that there's not risk associated with these compounds," stressed Griffiths. "And we wouldn't want to be a reason for an uptick for non-medical, uncontrolled use of this sort of thing."

Dr. Stephen Ross, clinical director of the NYU Langone Center of Excellence on Addiction in New York City, said he viewed Griffiths' work as a "landmark" in the field of hallucinogen research.

"I say this because we think of personality as being cemented in your 20s, certainly by your 30s," he said. "So the fact that openness was increased, seemingly permanently, after a single experience of psilocybin is quite remarkable.

"But, of course, as interesting as the implications for future therapies from this might be, the message should be that people should not try this at home or in any kind of uncontrolled environment," Ross added. "This is preliminary research that needs to be replicated. And replicated in a carefully controlled treatment environment."

More information

For more on hallucinogens, visit the U.S. National Institute on Drug Abuse.