More commonly known as a way to get high, the active ingredient of magic mushrooms may provide benefits previously unknown.
Psilocybin, the psychedelic chemical that causes euphoria and hallucinations when taking mushrooms, may also have impacts on fear learning and addiction withdrawal, according to a group of studies being presented at the Neuroscience 2023 press conference, the annual meeting of the Society for Neuroscience, on November 14.
"Studies suggest that certain psychedelic compounds show promise for treating a range of psychiatric disorders," Frederick Barrett, director of the Johns Hopkins Center for Psychedelic and Consciousness, who studies the mechanisms underlying the effects of psychedelic drugs, said in a statement.
"The research presented today is crucial in understanding what factors may influence the efficacy of these compounds, including sex, dose, and timing of administration."
One of the papers reveals that psilocybin can help treat nicotine withdrawal in mice, leading to fewer symptoms of withdrawal after treatment with the psychedelic.
The experimental mice were genetically modified to not express serotonin (5-HT) 2A receptors, meaning that psilocybin had no effect on them. These mice were seen to have no change in nicotine withdrawal symptoms, while non-modified mice did show a reduction in withdrawal.
"Psilocybin completely reversed somatic signs due to nicotine withdrawal in mice. The effect of psilocybin was lost in the 5-HT2A KO [knock-out] mice, establishing this receptor as a potential mechanism of this attenuation. Additionally, psilocybin decreased the expression of nicotine preference in mice in the [nicotine conditioned place preference] paradigm," the researchers wrote in the abstract.
"Psilocybin reduced the somatic signs of nicotine withdrawal and nicotine-conditioned reward in mice by action through the 5-HT2A receptor. These initial studies suggest that classical psychedelics like psilocybin may be a potential effective treatment for smoking cessation," they said.
The other studies reveal that psilocybin and another psychedelic compound, N,N-dimethyltryptamine (DMT), may have antidepressant effects, with some showing reduced fear renewal. This may have implications for treatments of fear-related psychological disorders such as phobias and post-traumatic stress disorder, as these are associated with responses to fear memories.
The researchers found that psilocybin did not change the rate of fear learning—learning to associate a stimulus with feeling fear—or extinction of this learned fear after the danger was removed in mice. Male mice were found to have a lower rate of fear reinstatement compared to females, however.
"There was no difference in freezing behavior in fear acquisition, nor fear extinction between mice that received saline or psilocybin," the researchers wrote in the abstract. "Interestingly, male mice that received psilocybin showed reduced fear renewal, which was not seen in females.
"What is even more striking is that an impairment of fear extinction was seen in animals that received DMT. Further research is needed to understand any sex-dependent effects of psychedelics, as well as dose and timing of drug administration," they said.
Another study being presented supports these findings, as it reveals that low doses of psilocybin enhance fear extinction differently between female and male rats.
The researchers taught rats to associate an electrical shock with a sound, leading to them developing a fear response to the sound. They then removed the electric shock and measured how long it took for the mice to no longer associate the sound with fear.
They found that after being treated with psilocybin, male rats learned that the sound had no threat faster than before, while female rats learned this more slowly than before.
"The low dose of psilocybin enhanced extinction learning in males but slowed extinction learning in females," the researchers wrote in the abstract.
"This differential impact of psilocybin on extinction was maintained during extinction recall the next day. Our findings suggest that a low dose of psilocybin augments extinction learning in males, but not females. The sex-dependent nature of this effect warrants additional research."
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Uncommon Knowledge
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Newsweek is committed to challenging conventional wisdom and finding connections in the search for common ground.
About the writer
Jess Thomson is a Newsweek Science Reporter based in London UK. Her focus is reporting on science, technology and healthcare. ... Read more
