Psilocybin Can Reduce Cravings In Alcohol Dependent Rats, And Now We Know Why


Dr. Katie Spalding

Katie has a PhD in maths, specializing in the intersection of dynamical systems and number theory.

Freelance Writer


Don't do it, Geoff! Image credit: kanashi/

Despite having a reputation as something of a hippie drug, psilocybin or “magic” mushrooms have actually been shown to have a wide range of legit medical benefits in recent years. It can relieve depression, improve creative thinking ability, and possibly even kickstart the evolution of the human species.

A new study, published today in the journal Science Advances, has found another potential benefit of psychedelic fungi: treating alcoholism. In a rat model of alcohol misuse and addiction, researchers found that alcoholism relapse was significantly reduced when the rats were given a dose of psilocybin.


“[P]silocybin administration was capable of restoring mGluR2 deficit in alcohol-dependent rats and thus could decrease relapse behavior,” explain the study authors. “Therefore, we conclude that psilocybin should be considered for clinical trials in alcohol-dependent patients.”

That mGluR2 is the key. It’s a particular type of protein found in our brains that helps us learn, remember, and feel things like pain and anxiety. It also allows us to get drunk, high on cocaine, and rabies. Basically, if glutamate receptors were movies, mGluR2 would be The Hangover.

Unfortunately, it’s also responsible for when we take those behaviors too far. The more alcohol a rat drank, the study found, the more mGluR2 they lost – and in an ironic feedback loop, the less mGluR2 the rats had, the more alcohol they craved.

“[A] corticoaccumbal mGluR2 deficit is both necessary and sufficient for diminished cognitive flexibility and increased drug craving … Prefrontal mGluR2 deficits can be caused by excessive alcohol and cocaine exposure,” the study explains. “We … demonstrate that pharmacological targeting of mGluR2 dysfunction via psilocybin may provide an effective strategy for relapse prevention in [alcohol use disorder].”


That’s because, as the researchers showed, a dose of psilocybin was able to undo the damage done by the booze: it could restore the mGluR2 that the alcohol abuse had destroyed. The effect was “highly significant,” the study notes, with a small dose of 1mg/kg performing as well as a dose 2.5 times the size.

Psilocybin was first seen to help alcohol dependency in 2015, with interest in the potential for this new therapy ramping up pretty quickly after that. But precisely why psilocybin seemed to help was not well understood – in fact, even the mechanism behind alcohol dependency remained mysterious. This new study provides not just a potential treatment, but an explanation: it’s an mGluR2 deficit.

Of course, as with any study whose results rely heavily on drunk rodents, there are some limitations. First and foremost: yes, this study was carried out on rats, and the results may not be generalizable to humans. In fact, they may not even be generalizable to rats, since the study notes that the particular family of rats used in the experiment reacted unexpectedly well to being alcoholics compared to other rats.

Nevertheless, the researchers think their results warrant further investigation – in particular, human trials.


“[W]e suggest performing an experimental medicine trial in alcohol-dependent patients to demonstrate improved cognitive flexibility in response to a single administration of psilocybin,” the authors write. “Second, we suggest performing a cue-elicited craving study in alcohol-dependent patients in the [MRI] scanner … following a single application of psilocybin.”

Should both these trials be successful, the researchers want to look into how well psilocybin stops relapse in humans. Until then, there’s just one thing to do: figure out where to buy some teeny-tiny sobriety chips.


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