A team of researchers has started to investigate whether psilocybin, a naturally occurring psychedelic compound found in so-called “magic” mushrooms, shows promise as a potential treatment for obesity and eating disorders.
Their initial results, published Translational Psychiatry, indicate that psilocybin does not lead to reduced body weight or food intake in obese mice. But the researchers don’t believe their findings, or lack thereof, should discourage additional studies evaluating the potential of psilocybin in humans.
Recent studies have provided initial evidence that psilocybin-assisted therapy might be effective in the treatment of addiction, leading the scientists behind the new research to wonder whether it could also help those who are struggling to control food cravings. In addition, a correlational study published in 2021 found that those who reported having tried a classic psychedelic drug at least once in their lifetime had significantly lower odds of being overweight or obese.
“Perhaps surprisingly, obesity is a rather treatment resistant disease that shares neuropathological similarities to mental disorders, such as addiction,” explained study author Christoffer Clemmensen (@ClemmensenC), an associate professor at the University of Copenhagen.
“Dysfunctions in homeostatic and reward circuitry can lead to ‘relapse’ in people with obesity, making it difficult to adhere to lifestyle and even drug interventions. Given that psychedelics are thought to enhance the plasticity of neural circuits, it may be that when combined with behavioural therapy, psychedelics might be powerful tools for ‘resetting’ long-held compulsive behaviors. Further, classic psychedelics act on the serotonergic system, and could have a direct effect on food intake by broad activation of serotonin (5-HT) receptors, emphasizing their potential benefits for obesity.”
For their new study, the researchers used mouse models of genetic obesity, diet-induced obesity, and binge-eating disorder to examine the effect of psilocybin on body weight and food intake. But they found no evidence that a single high dose of psilocybin or a daily microdosing produced significant metabolic or behavioral changes.
“We were surprised to see that psilocybin did not have at least a subtle direct effect on food intake and/or body weight in genetic and diet-induced models of obesity and overeating,” Clemmensen told PsyPost.
“Although we failed to discover major effects of psilocybin on mouse energy metabolism and behaviors associated with eating, we believe that there are nuances of the mode of action of psychedelics that cannot be appropriately captured in rodent models. Importantly, psilocybin was safe and had no adverse effects on the physiological parameters we tested in mice.”
Mouse models are an invaluable tool that allows scientists to study a wide range of conditions in a highly controlled setting, and they have aided in the understanding of complex genetic and biological processes that underlie many diseases.
While rodent models have helped to advance our understanding of addiction and other conditions, they are not perfect substitutes for human subjects. Ultimately, more research is needed to fully understand the effects of psychedelic substances on food intake in humans, the researchers said.
“The main caveat is translation,” Clemmensen explained. “Although animal models in general have been invaluable for neuroscience and metabolism research they might be inappropriate for testing health benefits of psychedelics.”
“I remain excited about this topic, psychedelics for treatment of obesity and eating disorders and I think we should start considering what sub-groups of patients could benefit from this drug class,” he added,
The study, “Acute and long-term effects of psilocybin on energy balance and feeding behavior in mice“, was authored by Nicole Fadahunsi, Jens Lund, Alberte Wollesen Breum, Cecilie Vad Mathiesen, Isabella Beck Larsen, Gitte Moos Knudsen, Anders Bue Klein, and Christoffer Clemmensen.
