People who take the hallucinogenic drug in “magic mushrooms” can experience long-lasting changes in their personalities, researchers reported Thursday.

A study involving 51 volunteers who took a single high dose of the hallucinogen psilocybin found 60 percent scored higher in psychological tests measuring the fundamental personality trait of “openness” for at least a year later, the researchers reported.

The findings, being published in the Journal of Psychopharmacology, mark the first time researchers have reported long-term changes in personality associated with taking a hallucinogen.

Openness includes traits such as having imagination, a strong sense of aesthetics, a tendency to have a lot of feelings, enjoying abstract ideas, being broad-minded and being interested in learning and doing new things. It typically does not change after the age of 30.

“Normally, if anything, openness tends to decrease as people get older,” said Roland R. Griffiths, a professor of psychiatry and behavioral studies at the Johns Hopkins School of Medicine who led the study.

The research, funded in part by the National Institute on Drug Abuse, involved volunteers who completed between two and five eight-hour sessions who were told they would receive a “moderate or high dose” of psilocybin during one session without knowing which one. During each session, the volunteers were asked to lie down on a couch, cover their eyes with a mask, listen to music on headphones and focus on what they were experiencing.

The subjects underwent a battery of tests at the beginning, one to two months after each session and then about 14 months after the last session to measure various aspects of their personality, including neuroticism, extroversion, openness, agreeableness and conscientiousness.

Some of the participants reported experiencing strong feelings of fear or anxiety for at least a part of the sessions they took psilocybin. But none reported any lingering negative effects, the researcher said.

The participants who experienced the long-lasting personality change had experienced what they described as a “mystical experience” while taking the drug. A “mystical experience” was defined as having a “sense of interconnectedness with all people and things accompanied by a sense of sacredness and reverence.”

Based on the findings, Griffiths said he thought the changes could be permanent, and that the drug could have therapeutic uses. He is currently studying whether psilocybin can help alleviate depression and anxiety among cancer patients, and aid smokers trying to kick the habit.

“There may be applications for this we can’t even imagine at this point,” Griffiths said in a news release. “It certainly deserves to be systematically studied.”