BY THE OPTIMIST DAILY EDITORIAL TEAM
Psilocybin, the primary component found in some hallucinogenic mushrooms, is still making waves in mental health research. As scientists look for novel treatments for depression, psilocybin is emerging as a promising contender. A recent study by Monash University researchers adds convincing evidence to the expanding body of research highlighting psilocybin’s potential for treating major mental health symptoms such as low optimism.
In a landmark study, the researchers discovered that rats administered psilocybin showed enhanced optimism and were more motivated to perform reward-related tasks. If these effects are replicated in humans, psilocybin could be an effective treatment for one of the primary symptoms of depression. “These exciting results show the mechanisms of how psilocybin may work to increase optimism in an animal model, which we hope may translate to humans as well,” said Professor Jakob Hohwy, co-senior author of the study and a professor at the Monash Centre for Consciousness and Contemplative Studies (M3CS).
Understanding the science behind psilocybin
The researchers used a computational model to look into how psilocybin influences the brain’s information-processing systems. According to information processing theory, the brain functions like a computer, accepting input, processing it, and giving an output. Scientists seek to adapt treatments for psychiatric diseases, including depression, by studying how psilocybin affects certain parameters in this model.
The study, published in Translational Psychiatry, comprised giving a single dosage of psilocybin (1.5 mg/kg) or saline to rats aged eight to nine weeks old. The rats were next assessed in a reversal-learning task, which required them to adapt to shifting reward-stimulus connections across 14 consecutive sessions. This exercise assesses cognitive flexibility, which is commonly hindered in those suffering from depression.
Optimism bias and cognitive flexibility: key findings
One of the study’s most noteworthy findings was that psilocybin increased rats’ optimism by encouraging more involvement with their surroundings. The rats administered psilocybin tended to achieve more rewards during the task than the control group, and they remained motivated throughout the experiment. In contrast, the control group engaged in fewer frequent tasks and spent considerably more time in their cages, indicating a withdrawal from reward-seeking behavior.
These findings are consistent with what experts refer to as “optimism bias”—the propensity to overestimate the frequency of favorable events while underestimating negative outcomes. The psilocybin-treated rats demonstrated this tendency by “forgetting” more about previous unfavorable outcomes after obtaining a reward, implying that the medication may help lessen loss aversion, which frequently affects people suffering from depression.
“Rats given psilocybin had more losses than the control group but still engaged more with the task, meaning they were less deterred from engaging despite the possibility of a loss,” the study’s authors wrote. This decrease in loss aversion could be essential to understanding how psilocybin restores optimism in people suffering from depression.
Future directions in psilocybin research
While the study provides fascinating insights, more research is needed to see whether these benefits can be repeated in humans. The potential for psilocybin to treat key symptoms of depression, such as apathy and decreased optimism, is quite promising, but the path to human use is still in its early stages.
“Insights into the mechanisms of psilocybin allow us to unpack who may benefit from psychedelic therapies as well as who these treatments may not be beneficial for,” said Beth Fisher, who led the study with Hohwy. “With many people around the world affected by depression, our ultimate goal is to help build an understanding of how psilocybin might be used to treat core symptoms people experience.”
The researchers’ next step will be to perform human trials to see if psilocybin may safely and successfully promote optimism in those suffering from depression. If the findings apply to humans, psilocybin could be a powerful new tool for treating a mental health crisis that affects millions across the world.
Source study: Translational Psychiatry—Psilocybin increases optimistic engagement over time: computational modeling of behavior in rats
