The Cognitive Effects of Psilocybin – Insights From Science
Introduction
Psilocybin, the active compound in certain mushrooms often called “magic mushrooms,” has been stirring up excitement in science and medicine for its remarkable ability to impact the brain. There have been tons of studies and research on the subject. Once dismissed and criminalized, it’s now sparking questions about its role in transforming mental health care and even how we understand the human mind.
Psilocybin is no newcomer to the scene. Indigenous cultures have used it for centuries in rituals and healing ceremonies, but modern science first took notice in the mid-20th century. Researchers began exploring its potential for psychiatric treatments, only to see progress grind to a halt in the 1970s when psychedelics were swept into restrictive drug laws. Fast forward to today, and we’re in the midst of a “psychedelic renaissance,” where psilocybin is once again under the microscope, showing promise for treating depression, anxiety, addiction, and more.
While the focus has been on psilocybin’s potential therapeutic effects, there’s a lot to be said about its effects on the brain on a cognitive level? Can it sharpen your attention, improve memory, or boost creativity? Or does it impair these functions? This article is a breakdown of a systematic review of studies on psilocybin’s effects on cognition. The study was published in Psychiatry and Clinical Neurosciences and is called, Impact of psilocybin on cognitive function: A systematic review.
Psilocybin and the Brain: A Primer
Unlike some recreational drugs that offer a fleeting “high,” psilocybin’s effects often go much deeper. It alters neural activity, changing the way different parts of the brain communicate with one another. This can lead to a phenomenon called “neuroplasticity,” where the brain temporarily becomes more flexible and adaptive. Think of it as loosening up rigid patterns of thought. This in turn contributes to helping people reframe negative beliefs, break out of mental ruts, or even spark new creative ideas.
While psilocybin is best known for inducing vivid hallucinations and a sense of “ego dissolution” (the feeling of losing one’s sense of self), it also impacts cognitive functions like attention, memory, and emotional processing. For example, during a psilocybin experience, people often report heightened empathy, bursts of creativity, and a sense of connection to others or the world around them.
Psilocybin’s effects aren’t just limited to the hours immediately following ingestion. Studies show that some cognitive and emotional changes can persist for weeks, even months. This is where psilocybin’s potential as a mental health treatment shines brightest. Rather than merely providing a temporary escape, it may offer lasting benefits by rewiring how the brain processes thoughts and emotions.
When it comes to psilocybin’s effects on cognitive function, there are still a lot of unanswered questions. While some studies suggest improvements in creativity and emotional processing, others highlight temporary impairments in attention or working memory, particularly during the acute phase (the hours following ingestion). This dual nature of psilocybin—both enhancing and impairing cognitive functions depending on the dose and timing—makes it a fascinating but complex area of study. For a deep dive into psilocybin’s mechanism for acting on the brain, check out this article.
While it’s extremely important to understand how to safely use psychedelics like psilocybin, another important area of investigation is understanding how to unlock its full potential. The study will help us get a little bit closer to that understanding.
How Researchers Analyzed Psilocybin’s Effects
The study reviewed 20 published research papers that evaluated psilocybin’s effects on cognitive function in humans. These papers represented a mix of clinical trials and observational studies, offering a broad range of insights into psilocybin’s impact on attention, memory, emotional processing, executive function, and more. The researchers also included data from eight registered clinical trials, many of which explored psilocybin’s therapeutic potential for mental health conditions such as depression and treatment-resistant depression (TRD).
How the Data Was Gathered
The researchers conducted a systematic review across three major databases—MEDLINE, PsycINFO, and Embase—searching for studies related to psilocybin and cognition. They left no stone unturned, also scouring Google Scholar and ClinicalTrials.gov for additional data and manually reviewing reference lists from relevant papers. Using carefully selected keywords like “psilocybin,” “cognition,” and “memory,” they ensured their search captured a comprehensive range of studies.
To streamline the process, all search results were imported into a specialized review management platform called Covidence. From there, two independent reviewers screened each study to determine whether it met strict inclusion criteria.
These criteria included:
- Focus on the effect of psilocybin on cognitive function in humans.
- Use of neurocognitive assessments to evaluate cognitive outcomes.
- Exclusion of participants with conditions like dementia, traumatic brain injuries, or mild cognitive impairment.
The final sample included 20 studies involving a total of 2,959 participants. These studies ranged from evaluating psilocybin’s effects in healthy individuals to exploring its impact on those with psychiatric conditions such as depression and anxiety.
What Did They Measure?
The studies assessed a variety of cognitive domains, including:
- Attention and Processing Speed: Tasks to measure focus and reaction time.
- Memory (Short-Term, Working, and Episodic): Tests like word recall and spatial memory tasks.
- Emotional Processing: Recognizing facial expressions or responding to emotionally charged words.
- Cognitive Flexibility and Creativity: Problem-solving and “thinking outside the box.”
- Executive Function: Skills like planning, decision-making, and multitasking.
Depending on the study, psilocybin was administered in different doses—ranging from microdoses (0.5 g of dried mushrooms) to higher doses (25–30 mg of psilocybin). Assessments were conducted during both the acute phase (within hours of ingestion) and the post-acute phase (weeks or months later).
Quality Assurance
To ensure the reliability of the findings, the researchers used the Cochrane Collaboration’s tool to assess the risk of bias in randomized trials. This tool evaluates potential issues such as incomplete data, randomization methods, and outcome reporting. By adhering to such rigorous standards, the review ensured that only high-quality studies contributed to the overall analysis.
What Made This Approach Unique?
What sets this systematic review apart is its focus on psilocybin’s effects across a wide array of cognitive functions, rather than narrowing in on just one domain like memory or attention. Additionally, by including data from both clinical and non-clinical populations, the researchers provided insights into how psilocybin affects not only healthy individuals but also those dealing with mental health challenges.
This methodical approach ensures that the findings provide a balanced perspective, highlighting both the potential benefits and limitations of psilocybin as a therapeutic tool.
Key Findings: Psilocybin’s Impact on Cognitive Functions
After combing through 20 studies and analyzing data from nearly 3,000 participants, researchers unveiled a nuanced picture of psilocybin’s impact on various cognitive functions. The findings show that psilocybin’s effects are far from one-size-fits-all. Instead, they vary depending on the cognitive domain being measured, the dose, and whether the effects are assessed during the acute phase (right after ingestion) or the post-acute phase (weeks or months later). Here’s what they uncovered:
- Attention and Processing Speed
Acute Effects: Psilocybin showed a consistent trend of impairing attention and slowing reaction times immediately after ingestion. Tasks requiring sustained focus or visual attention, like the Frankfurt Attention Inventory (FAIR), revealed reduced performance during the acute phase.
Post-Acute Effects: On the bright side, one study observed a non-significant trend toward improved sustained attention 29 days after psilocybin use. While not conclusive, it hints at the possibility of long-term benefits in certain cognitive domains.
- Working Memory
Acute Effects: Mixed results emerged here. In higher doses (above 0.25 mg/kg), psilocybin impaired working memory, as seen in tasks like the Spatial Span Test and AX Continuous Performance Test. However, other studies showed no significant effects at lower doses.
Post-Acute Effects: Interestingly, one study reported a potential improvement in working memory a month after psilocybin treatment. This suggests that while short-term disruptions may occur, psilocybin could help enhance memory-related functions in the long run.
- Emotional Processing
Psilocybin had a profound impact on emotional processing.
In the acute phase, participants showed a stronger bias toward positive emotions, with increased recognition of positive words and facial expressions. However, results were mixed regarding emotional response accuracy.
In individuals with treatment-resistant depression (TRD), psilocybin-assisted therapy improved emotional processing a month later, with participants demonstrating faster and more accurate recognition of emotions.
- Social Cognition and Empathy
Psilocybin appeared to enhance emotional empathy (the ability to feel others’ emotions) in the acute setting. However, there was no significant change in cognitive empathy (the ability to understand others’ emotions).
Studies examining post-acute effects and microdosing found no noticeable changes in empathy or social cognition, highlighting that the acute experience may be key to these benefits.
- Cognitive Flexibility and Creativity
Acute Effects: Initially, psilocybin impaired creative thinking, reducing participants’ ability to come up with novel solutions (divergent thinking) and limiting their problem-solving skills (convergent thinking).
Post-Acute Effects: A more optimistic picture emerged here. Days or weeks after psilocybin use, participants displayed enhanced cognitive flexibility and creativity, generating more unique ideas and showing greater openness to new concepts.
- Memory and Learning
Psilocybin had minimal effects on episodic memory (memory of past experiences) in the post-acute phase. However, during the acute phase, it increased access to remote associations, meaning participants were better at connecting unrelated concepts—an intriguing finding for creativity research.
Word recall and recognition accuracy showed mixed results, with some impairments observed at higher doses.
- Executive Function
Acute Effects: Psilocybin impaired executive functions like decision-making and multitasking, as measured by tests such as the Digit Symbol Substitution Test (DSST). Participants made fewer attempts and showed slower response times under the drug’s influence.
Post-Acute Effects: In contrast, individuals with treatment-resistant depression exhibited improvements in executive function three weeks after taking psilocybin. Higher doses were linked to greater benefits, suggesting a dose-dependent relationship in this domain.
A Complex Dose-Dependent Relationship
One of the study’s most striking conclusions was the dose-dependent nature of psilocybin’s effects.
Low to Moderate Doses: These often had minimal or mixed effects on cognitive performance.
Higher Doses: These were more likely to impair cognition in the short term but were also associated with longer-term improvements in emotional processing, creativity, and flexibility.
The Role of the Post-Acute ‘Afterglow’
A recurring theme across the studies was the post-acute afterglow—a period lasting days to weeks after psilocybin use during which participants reported enhanced emotional openness, improved problem-solving, and greater cognitive flexibility. This phase is thought to result from psilocybin’s effects on neuroplasticity and serotonin receptors, helping the brain rewire itself in healthier ways.
Clinical Implications and Future Directions
The research on psilocybin is undeniably promising, but what does it all mean for clinical practice and the future of mental health care? This section explores how psilocybin might shape treatment landscapes, its potential therapeutic uses, and what we need to focus on next to make its clinical applications a reality.
- A New Tool for Mental Health Treatment
Psilocybin has already demonstrated potential as a game-changer in mental health care. Its ability to target conditions resistant to conventional treatments, such as major depressive disorder (MDD) and treatment-resistant depression (TRD), is a major breakthrough.
For Depression: Studies have shown that psilocybin-assisted therapy not only alleviates symptoms but can also lead to long-lasting improvements in mood and emotional resilience.
For Emotional Processing: In TRD patients, psilocybin appears to recalibrate emotional reactivity, allowing individuals to better process and regulate their feelings, which is crucial for long-term recovery.
For Anxiety and PTSD: Preliminary findings suggest psilocybin could reduce fear-based responses and improve emotional flexibility, making it a candidate for treating PTSD and anxiety disorders. Check out this article to learn more.
- Enhancing Cognitive Function and Creativity
Beyond its role in mental health, psilocybin holds potential for cognitive enhancement:
Cognitive Flexibility: Research indicates that psilocybin can disrupt rigid thought patterns and promote cognitive flexibility, making it useful for people stuck in negative or unproductive mental loops.
Creativity and Problem-Solving: Psilocybin’s ability to enhance divergent thinking and novelty generation opens doors to its use in creative fields or for individuals seeking fresh perspectives in their personal or professional lives.
These benefits are not limited to clinical populations—they could also support healthy individuals looking to foster growth, creativity, and emotional intelligence.
- Integration Into Existing Therapies
Psilocybin’s effects go beyond the drug itself; its success often hinges on the integration of the psychedelic experience into therapeutic frameworks. This integration involves:
Psychedelic-Assisted Therapy: Combining psilocybin with psychotherapy enhances its benefits, as therapy provides a space for individuals to process and make sense of their psychedelic experiences.
Post-Acute Integration Practices: The “afterglow” period, characterized by emotional openness and cognitive flexibility, is an ideal time for reflective practices such as journaling, meditation, or structured therapy to reinforce insights gained during the psychedelic experience.
- The Need for Ethical Guidelines
As interest in psilocybin grows, establishing ethical guidelines for its use is critical. Questions to consider include:
Who Should Have Access? Should psilocybin treatments be reserved for clinical populations, or should healthy individuals seeking self-improvement also have access?
Training Clinicians: Clinicians need specialized training to administer and guide patients through psilocybin therapy safely and effectively.
Preventing Misuse: Safeguards must be in place to prevent recreational misuse or over-reliance on psilocybin as a “magic bullet.”
- Moving Beyond the Stigma
Psilocybin’s potential is hindered by its historical stigma as a recreational drug. Education and advocacy will be key in reframing public perceptions:
Highlighting its evidence-based therapeutic benefits can shift the conversation from “drug” to “medicine.”
Building trust with the public will be essential as clinical applications expand.
- Future Research Priorities
Although we’ve made significant progress, there’s still a lot to learn. Future research should focus on:
Standardizing Protocols: Developing consistent dosing regimens and treatment frameworks to ensure reliable results across studies.
Long-Term Effects: Exploring the enduring cognitive and emotional impacts of psilocybin to better understand its therapeutic potential and possible risks.
Diverse Populations: Most studies focus on healthy, middle-aged individuals. Future research must include broader demographics, such as older adults, those with varying cultural backgrounds, and individuals with different mental health conditions.
Mechanisms of Action: Further investigation into how psilocybin interacts with serotonin receptors, neural networks, and neuroplasticity will deepen our understanding of its effects.
- Legal and Regulatory Changes
For psilocybin to become a mainstream therapeutic option, significant legal and regulatory hurdles must be addressed:
In Canada, psilocybin is still classified as a controlled substance, but there are promising steps toward decriminalization and therapeutic use.
Regulatory changes must ensure access while maintaining rigorous safety standards, possibly mirroring how cannabis transitioned from stigma to medical acceptance.
- A Broader Vision for Mental Health
Perhaps one of psilocybin’s most exciting implications is its potential to revolutionize how we approach mental health care. Unlike traditional treatments that often aim to suppress symptoms, psilocybin appears to offer a pathway for deep, transformative healing:
By encouraging individuals to confront and process their emotions, psilocybin may address root causes of mental health conditions rather than just managing symptoms.
Its ability to foster a sense of connection—whether with oneself, others, or the world—could reshape how we think about well-being and fulfillment.
Final Thoughts on the Future
Psilocybin is more than just a drug; it’s a potential catalyst for personal and societal transformation. While challenges remain, the research to date paints a compelling picture of a future where psilocybin plays a key role in addressing mental health crises, improving cognitive function, and even sparking creativity. As we continue to explore its potential, maintaining a balance between innovation and caution will be vital to ensure its safe and ethical integration into modern healthcare.
References
https://www.psychologicalscience.org/observer/psychedelic-research-reborn
