Rat Study Examines Psilocybin as Treatment for Autism Spectrum Disorder

Little by little, researchers are exploring the effects of psilocybin on people living with autism spectrum disorder (ASD)—and the evidence showing the compound’s promise in treating the condition continues to grow.

There is no cure for ASD or similar conditions, so many families resort to behavioral therapies, with few other options on the table. But a rise in alternative therapies involving cannabis or psychedelics is forming, with notable promise from psilocybin.

A study published in the journal Psychopharmacology examined the effects of psilocybin microdoses on Fragile X syndrome (FXS)—a leading cause of autism. FXS is the most common form of inherited intellectual disability (ID) and the leading cause of ASD involving one gene. 

Researchers gave different doses of psilocybin to test rats and then tested their cognitive abilities. They examined cognitive deficits displayed by the recently validated Fmr1-Δexon 8 rat “model of ASD,” which is also a model of FXS, and how psilocybin plays a role. 

The study, “Psilocybin mitigates the cognitive deficits observed in a rat model of Fragile X syndrome,” examined rat microdoses of psilocybin for 5-14 day periods.

Serotonin insufficiencies during childhood may have an impact on brain patterning in neurodevelopmental disorders, manifesting as behavioral and emotional symptoms, researchers explained in the study. And since psilocybin stimulates serotonergic signaling, it may offer promise as effective early interventions for developmental disorders such as ASD and FXS.

Researchers first gave rats a single large dose of psilocybin and then tested any changes to their cognitive abilities, finding some improvements. Rats that did not have FXS led to reductions in cognitive performance. 

Researchers then gave another group of rats microdoses over the course of five days, giving them cognition tests daily. 

They observed improvements in all of the rats to the extent that their cognition results were nearly identical to rats that did not have FXS. Researchers ran the experiment again, extending it to two weeks, and they found identical results.

“Our results revealed that systemic and oral administration of psilocybin microdoses normalizes the aberrant cognitive performance displayed by adolescent […] rats in the short-term version of the novel object recognition test—a measure of exploratory behavior, perception, and recognition,” researchers wrote.

The data supports existing theories of how psilocybin may affect the production of serotonin and thus help people living with cognitive and emotional conditions.

“These data support the hypothesis that serotonin-modulating drugs such as psilocybin may be useful to ameliorate ASD-related cognitive deficits. Overall, this study provides evidence of the beneficial effects of different schedules of psilocybin treatment in mitigating the short-term cognitive deficit observed in a rat model of FXS.”

The goal is to eventually commence clinical trials of psilocybin on human patients. 

Researchers across the board are experimenting with psilocybin (as well as several cannabis compounds) to treat ASD and other autism-related conditions.

One Canadian research team has studies already underway. Dr. Max Jones and Dr. Gale Bozzo, two professors at University of Guelph’s Ontario Agricultural College (Department of Plant Agriculture), received a Health Canada “dealer’s license” on Oct. 25. The license permits the cultivation of psilocybin mushrooms, and is one of the first universities in Canada to be permitted to do so.

Dr. Melissa Perreault, Professor in Ontario Veterinary College’s Department of Biomedical Sciences, has experience and has previously involved studies of the molecular and cellular mechanisms associated with medical conditions like depression or ASD. Her plan is to examine the signaling pathways that psilocybin might affect.

More research is needed to determine psilocybin’s efficacy for the treatment of ASD in human trials.