PDF Summary:How to Change Your Mind, by Michael Pollan

Did magic mushrooms contribute to making us human? In How to Change Your Mind, Michael Pollan traces the long and complex history of humans’ relationship with psychedelics and examines their potential use for mental health treatment today. He delves into the complex legal and cultural issues surrounding psychedelics and considers what their re-emergence might mean for our society as a whole.

Michael Pollan is an author, journalist, and professor. He is best known for his books The Omnivore’s Dilemma and In Defense of Food, which have helped shape the public’s understanding of the modern food system. But after learning about terminal cancer patients who were given psilocybin to help ease the fear of death, Pollan threw himself into research on psychedelics—which included personal experimentation.

In this guide, we’ll situate Pollan’s research within the current field of psychedelic trials and review some of the guidelines for mitigating the dangers of psychedelic research. We’ll also probe ancient history to provide further context for humans’ complex and enduring relationship with these substances.

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Nixon’s “War on Drugs” Was a Culture War

President Nixon's "War on Drugs" campaign intensified the crackdown on all drug use, including psychedelics. The administration emphasized criminalizing drug offenders rather than pursuing treatment or prevention strategies. Nixon declared drugs "public enemy number one." Anti-drug messages were disseminated through various media channels, including television, print media, and public service announcements. This campaign successfully created a negative public perception of psychedelics through fear tactics and demonization.

And it’s no coincidence that the “War on Drugs” historically coincides with the civil rights and antiwar counterculture movements—it was a direct response to those. One of Nixon’s closest advisers, John Ehrlichman, acknowledged in a 1994 interview that Nixon was specifically targeting the antiwar left and Black people with this campaign. He says “We knew we couldn’t make it illegal to be either against the war or Black,” so instead they focused on getting the public to associate hippies and Black people with drugs—like marijuana, LSD, and heroin—and then criminalizing those drugs.

While Leary and others like him can be partially blamed for the widespread banning of psychedelics in both academia and society as a whole, Pollan points out that their haphazard and unruly approach to experimentation was probably necessary. This was uncharted territory, and they could only have learned how context-dependent psychedelic experiences are by trying out different methods. They ultimately learned that psychedelic-assisted therapy works best in a controlled and guided setting, and the current phase of research is taking those findings seriously and implementing them.

Research on Psychedelics is Revived

After a decades-long ban, a few researchers attempted in the 1990s to resurrect interest in the study of psychedelics for mental health and spirituality. But it was only in 2006 that a new renaissance of psychedelic research was kicked off with another Johns Hopkins study. It was described in a paper titled “Psilocybin Can Occasion Mystical-Type Experiences Having Substantial and Sustained Personal Meaning and Spiritual Significance.” Pollan tells us that this work made a few crucially important contributions to the history and understanding of psychedelics:

• It opened up a new dialogue and interest in the scientific study of psychedelics.
• It started a conversation about the distinction between psychedelics and other types of “drugs,” leading to a wider recognition that psychedelics are generally much safer, have therapeutic use, and are non-addictive.
• It bridged a gap between science and spirituality. This study looked at the spiritual experiences of healthy participants, acknowledging that psychedelic experiences can have inherent value for humanity as a whole, not just for treatment of illness.

(Shortform note: Several similar studies have been conducted since the 2006 Johns Hopkins one, with consistent results. A 2011 study showed that while 39% of volunteers experienced extreme anxiety or fear while taking the drug, 72% reported having mystical experiences. At follow-ups one month and 14 months later, volunteers said that these experiences had substantial personal and spiritual significance, and they reported sustained positive changes in mood, attitudes, and behaviors.)

Part 2: The Science of Psychedelics

Let’s turn now to a discussion of what recent research has found about how psychedelics work, both in terms of the subjective psychological experiences they trigger and their physiological effects on the brain.

There is now mounting scientific evidence that psychedelics have the potential to treat mental health problems that can be otherwise treatment-resistant. Pollan tells us that two recent studies have shown an 80% success rate in the alleviation of anxiety and depression among cancer patients. Similar results have been achieved with studies using psychedelics to treat addiction. These kinds of success rates, he says, are unprecedented with any other form of treatment. But how do they work?

Unlike other pharmaceutical treatments, Pollan explains that with psychedelics it may not necessarily be the chemical reaction in the brain that’s therapeutic but the experience resulting from it. And that experience isn’t centered on the “visions” the subject has, but on the revelations they have from those visions. In this section, we’ll look at how psychedelic experiences are described, as well as what researchers have learned about what’s going on in subjects’ brains to produce these experiences.

(Shortform note: A 2021 study by researchers at Johns Hopkins examined the question of whether psychedelics could be useful from a solely biochemical standpoint, or whether the subjective experience of the trip is necessary. The study concludes the latter, stating that the neurobiological mechanisms are “likely necessary but not sufficient” to confer lasting therapeutic benefits.)

How Is This Research Conducted?

In reviewing the large volume of psychedelic research from the 1950s through today, Pollan notes that there have been a number of conflicting conclusions—some studies have had significantly higher success rates than others. He suggests that one factor contributing to disparities in results is the difference in “set and setting,” a crucial factor in psychedelic experimentation. “Set” refers to the mindset of the person at the time they take the psychedelic, and “setting” to the space and context within which the drug is taken. Leary stressed the vital importance of these factors for the outcome of the experience, and they remain central to the approach to psychedelics in research today.

(Shortform note: A long-recognized important element of set and setting in psychedelic therapy is music. Using principles from music psychology, University of Copenhagen researchers have developed their own playlist specifically designed to facilitate psychedelic therapy. They used four criteria in the selection of musical pieces: 1. An intensity appropriate to the psychedelic experience, 2. Culturally diverse styles and genres, 3. Any vocals should be in unfamiliar languages, and 4. No obvious religious references. The playlist—The Copenhagen Music Program for Psilocybin—is available on Spotify.)

Pollan describes how these studies are conducted in clinical settings. He says participants are put in a comfortable room at the research center with a guide who is trained to direct the subject’s experience. The rooms are generally created to be pleasant, tranquil spaces, with soothing music playing. Guides may give the subject a description beforehand of what they’re likely to experience, and the subjects are always asked to relax and allow the experience to unfold. Having a guide there to remind the subject of this mitigates the risk of them becoming too fearful and going into a negative trip.

According to Pollan, subjects may be primed to expect to feel like they may be dying, dissolving, or losing themselves, and reassured that they shouldn’t be afraid because they will come back to reality. They should just let it happen, in order to get the fullest experience. They may also be told to expect mystical experiences and to fully embrace them.

Pollan points out that some have challenged the scientific nature of these methods, pointing out that this priming creates an expectancy effect—in other words, the researchers telling subjects what to expect necessarily influences what they'll experience. Pollan explains, however, that most researchers dismiss this concern, because (a) it’s unavoidable—they have to do this for the safety of the subjects, to ensure that they don’t have “bad trips,” and (b) this research is specifically about how psychedelics might be used to bring about healing and/or these mystical experiences, so specifically trying to induce that is within the objectives of the study.

Guidelines for Clinical Psychedelic Trials

The Johns Hopkins Center for Psychedelic and Consciousness Research, launched in 2019, is the first research center of its kind in the US and the largest in the world. This center is at the forefront of current psychedelic research, and it received its first federal grant from the National Institutes of Health in 2021—the first federal grant for this kind of research awarded in more than 50 years.

The Johns Hopkins team has developed a set of guidelines for safety in testing psychedelics on human subjects. This guide addresses several potential measures of risk associated with psychedelics:

• Physiological toxicity: There is no evidence for neurotoxic effects from LSD, psilocybin, or mescaline. MDMA, which is in a different class of drug, has the potential for some neurotoxic effects at high doses, but at therapeutic doses is considered safe.

• Abuse and dependence: Psychedelics have low potential for addiction and are considered safe to administer without risk of dependency.

• Psychological distress and dangerous behavior during the experience: The greatest risk associated with psychedelics is the risk of a “bad trip”—an experience characterized by acute psychological distress, anxiety, fear, and paranoia. This distress can potentially lead to dangerous behaviors, and although this is rare, researchers must be prepared to mitigate this risk and ensure the safety of the subject.

• Prolonged psychosis: In extremely rare cases, a psychedelic session could trigger a state of psychosis lasting for days or even months. This only happens in approximately 1.8 out of every 1,000 cases and has been associated with prior serious mental health conditions. For this reason, people with certain conditions, such as schizophrenia and bipolar I or II disorder, are now excluded from participation in psychedelic trials.

• Lasting perceptual abnormalities: Sometimes referred to as “flashbacks,” some subjects can experience a degree of altered perception after the psychedelic session is over. Recreational users of psychedelics report having these experiences more often than research subjects, and many report them as mild and not unpleasant. Research subjects should be made aware of the possibility, although with careful screening of subjects, it’s rare.

The Indescribability of the Psychedelic State

One of the biggest challenges with understanding how psychedelics work is that the experiences themselves are notoriously difficult to describe—participants almost always express a lack of ability to put the experiences into words. When they do describe them, the experiences tend to sound like hallucinatory or dream-like events, or even like spiritual clichés—for example, the description that “everything is love” or the sense of “oneness with the universe.”

Other common descriptions of psychedelic experience include:

• The feeling that one communicated with God, or became a god oneself
• The dissolving of one’s sense of self and/or the merging of self with others/everything
• The realization that death is an illusion and that consciousness survives it
• The sense that one is being born or giving birth (in one of his trips, Pollan experienced the feeling that he was giving birth to himself)
• A deep sense of connectedness with, and reverence for, nature
• Encounters with loved ones, alive or dead

These trips are usually accompanied by vivid sensory experiences of the outer and/or inner world. Psychedelic-assisted therapy often takes place with a mask covering the subject’s eyes, so the subject experiences all of their “visions” in their mind. But those who have psychedelic experiences in a non-clinical setting, without their eyes covered, tend to experience the outer world, especially nature, as particularly colorful, beautiful, and awe-inspiring.

Pollan presents two possible explanations for what happens when one undergoes a psychedelic experience:

1. The chemicals act on the brain to trigger activity that produces hallucinatory experiences. Or,
2. The chemicals open up our perception to real things that we don’t perceive in our normal waking consciousness.

But, upon reflecting on these two possible explanations, he asks: Does the distinction really matter? When talking about experiences like “oneness with the universe,” how can you distinguish between whether it was a “real” experience or a drug-induced hallucination? Pollan ultimately concludes that it’s an irrelevant question, because whatever chemical reaction is happening, the insights, revelations, and psychological effects are undoubtedly as real as anything else—and maybe more so.

The Ancient Greek Secret of Dying Before Dying

In The Immortality Key, Brian Muraresku makes a connection between the descriptions of modern psychedelic research subjects and those of the Eleusinian Mysteries in ancient Greek literature. The Mysteries were a secret cult practice at the heart of the religious tradition in Greece that existed for almost 2,000 continuous years. According to Muraresku’s research, in descriptions of the Eleusinian Mysteries, it’s said that the ancient secret was that one must die before dying. Initiates reported undergoing a transformative experience involving a metaphorical death and rebirth and emerged with a sense of their own immortality.

These descriptions are among Muraresku’s evidence supporting his argument that participants in the Mysteries were consuming psychedelics. The theme of death, rebirth, and immortality resurface often in descriptions of psychedelic experiences, from cultures around the world and throughout history. He also points to ancient Greek sources stating that the ritual wine was a “drug against grief” and a “treatment for misery,” and that without these rituals life would be unlivable. This is consistent with modern-day psychiatric research such as that at Johns Hopkins, which suggests these treatments have great potential for healing psychological trauma and easing end-of-life suffering and fear of death. Muraresku believes we could be on the verge of rediscovering the secrets that ancient Greeks believed made life worth living.

What Do Psychedelics Do to the Brain?

While research into the neurological effects of psychedelics is young, and researchers haven’t yet pieced it all together, some theorize that the substances may affect the way our brains filter or interpret information. Pollan says this research challenges conventional notions that the experiences are “hallucinations.”

Researchers at Imperial College in London in 2009 looked at brain scans of people undergoing psychedelic experiences with psilocybin. They expected to see increased brain activity, and that was the case for some regions, including those associated with emotions and memories—particularly otherwise subconscious ones. Considering the experiences people describe, this was not surprising. But what was surprising was the reduced activity in the “default mode network”—a network of brain regions responsible for our sense of self as a distinct individual.

(Shortform note: Higher connectivity in the default mode network is also seen in depressed and lonely people. This is because these regions are associated with rumination, or mentally fixating on oneself and one’s problems, rather than being fully in the present. Relaxation techniques like mindfulness meditation quiet down this network, and experienced meditators have consistently less active default mode networks.)

This network is also responsible for filtering information from the outside world. Pollan says this filter allows us to operate more efficiently by allowing only the most important pieces of information in at any given time. So, he explains, because this default mode network is suppressed during a psychedelic experience, that means the brain is letting in sensory input that’s normally restricted. We know, for example, that people see colors differently (often perceiving them as brighter) and hear music in a more intense and nuanced way under the influence of psychedelics.

So, Pollan says the brain research suggests that the way we perceive things in the altered state could be the unfiltered reality, while our brains usually act as filters—weeding out all the “unnecessary” information—to simplify our everyday experience. In other words, he says one could argue that our everyday consciousness is essentially a hallucination in itself—it’s composed only of the information the brain lets in and is processed against our prior experiences. And Pollan says it’s likely that this one particular mode of consciousness evolved to be our default one because it best allows us to efficiently complete tasks necessary for survival. But he says it’s only one of multiple possible modes of perception.

Psychedelics Increase Entropy in the Brain

Entropic Brain Theory says that the degree of entropy—or, disorder—in our brains determines how we experience life. While it would seem that a disordered brain would be dysfunctional, this theory says that many mental health conditions involve too much rigidity in the brain. It posits that consciousness exists in two forms: a primary mode and a secondary mode. Primary consciousness is associated with an instinctual state, like that of early humans, young children, and those suffering from psychosis. Secondary consciousness is associated with our normal waking consciousness, in which we have a strong sense of self and our brains are filtering out information that’s considered unnecessary.

Psychedelics shift our brains temporarily into primary consciousness mode. This is why they can shake people out of the habitual ways of thinking associated with trauma, depression, anxiety, and addiction. And it’s also why they can also be highly destructive for people with psychotic tendencies or other forms of mental illness that involve disordered states of mind.

Pollan Goes on Trips of His Own

In the course of research for this book, Pollan decided to undertake his own personal experimentation with psychedelics. As an American man in his 60s, he’d long been aware of psychedelics but had never tried them. After interviewing dozens of people, and hearing so many stories of transformation, healing, and realization, Pollan was driven to see if he could also derive some benefit from these substances. He knew this would be the only way to truly understand the subject. So he confronted his fears and used his connections from this book’s research to arrange some trips for himself.

Pollan’s experiences mirror those described in the research. For example:

• Trip #1—Psilocybin mushroom tea: For his first experiment, Pollan made a relatively mild brew of mushroom tea. This trip was unguided at his home. He describes a heart-opening feeling of being one with nature.
• Trip #2—LSD: Pollan undertook this trip with a professional guide, who gave him a relatively mild, but significant, dose of LSD. During this experience, he was able to process some deep emotional issues around his loved ones. Afterward, he felt like he’d had several years of therapy in just a few hours.
• Trip #3—Psilocybin mushrooms: In this experiment, Pollan ate a large psilocybin mushroom under the guidance of an experienced healer. He had a calm and serene experience that revealed to him that “there is life after ego death.” In this state, he describes being free from fear, desire, expectation, and judgment. It gave him a sense of reconciliation with death—both his own and that of his loved ones.
• Trip #4—“The Toad”: For his fourth psychedelic experience, Pollan braved one of the most powerful psychoactive agents—a substance called 5-MeO-DMT, which is obtained from the secretion of a toad. Under the guidance of an expert in the substance, he experienced a period of extreme terror and dissolution of self, followed by equally intense bliss and the feeling of being reborn into the world with immense gratitude for his existence.

Reflecting on his varied psychedelic experiences, one of Pollan’s major revelations was that our consciousness exists beyond our sense of self. He realized there is nothing to fear from the loss of one’s ego or sense of separate self, as it was not a frightening experience (apart from the initial fear during the toad experience). He realized that this explains why psychedelic therapy can be so beneficial for patients facing terminal illnesses.

(Shortform note: Psychedelic therapy shows great promise for addressing the fear and depression experienced by terminally ill individuals. By facilitating psychological well-being, promoting meaning-making, and inducing transformative experiences, psychedelics offer a unique avenue for dealing with existential crises. A 2016 study found that psilocybin-assisted therapy led to significant reductions in depression, anxiety, and existential distress in cancer patients, which was sustained at a six-month follow-up. In 2023, however, the only place psilocybin can be legally used for palliative care is in the state of Oregon, which will be implementing training programs for psychedelic facilitators.)

Part 3: The Social and Cultural Implications of Psychedelics

Pollan explains that, in addition to individual mental health uses, psychedelics have important social and cultural implications for human society—in the past, present, and future. Psychedelics may have contributed to our cognitive and spiritual evolution and have the potential to better our world. In this section, we’ll discuss the ways that psychedelics could have helped early hominids to evolve into the self-aware homo sapiens we are today, as well as how these substances could help get us out of some of our modern messes.

(Shortform note: The oldest known evidence of humans using psychedelic mushrooms comes from a cave painting at Tassili N’Ajjer in Algeria, dating from around 7,000 to 9,000 years ago. Known as the Tassili Mushroom Figure, this artwork depicts what scholars believe to be a shaman dancing with hands full of mushrooms. This indicates the use of these mushrooms for ceremonial purposes, providing further evidence that they were likely a psychoactive variety.)

The Stoned Ape Theory

One question posed by Pollan, and which other researchers have pondered, is: Why would these plants and fungi evolve with properties that affect the human mind this way? Some researchers believe that the production of these chemicals by plants and fungi is in service to a symbiotic relationship with humans. And some researchers even suggest that these altered states of consciousness may have been crucial for humanity’s evolution.

In 1992, ethnobotanist Terence McKenna proposed the “Stoned Ape Theory.” His hypothesis was that the cognitive development of hominids was due to their consumption of psilocybin mushrooms, which caused an evolutionary leap in consciousness. The theory suggests that this leap allowed for the development of language, religion, and other forms of symbolic thought—traits that distinguish humans from any other species. Pollan points out, though, that the theory has been contested by other researchers, who argue that there’s no concrete evidence to support it.

The effect of these chemicals on humans could be explainable by arguing that they’re toxins, meant to “poison” predators as a self-defense mechanism. However, Pollan learned from mycologist Paul Stamets that human ingestion of mushrooms actually helps the fungi, as the consumer will eventually eliminate their spores elsewhere. Stamets argues that the psilocybin is more likely an attractant for hosts rather than a deterrent to predators. And more than just a reproductive strategy, Stamets believes there’s a higher intelligence on Earth that’s attempting to communicate with us through fungi. He argues that fungi are intelligent and that they offer their mind-altering properties to us in exchange for our spreading of their spores.

Although Pollan is skeptical of some of Stamets’s more radical claims, he admits that his own psychedelic experiences have inspired a feeling of a connective consciousness pervading all of nature.

Are Psychoactive Compounds Attractants or Repellents?

Scholars don’t necessarily agree with Stamets’s hypothesis that fungi developed psychoactive properties to attract humans. Some argue that the psilocybin is meant to deter insect predators. Because these fungi tend to grow in environments with many insects, typically in animal dung and rotting wood, they may have developed these properties to interfere with the insects’ neurotransmitters. Scientists have shown that interference with flies’ neurotransmitters in this way decreases their appetite.

However, even if psychoactive fungi didn’t intentionally co-evolve symbiotically with humans, there’s scholarly evidence to support the claim that they may have facilitated our ancestors’ evolution and survival in several ways, including:

• Helping them cope with challenges and think more flexibly, contributing to creative problem-solving in challenging times

• Helping them manage psychological distress and health problems

• Improving social interactions and relationships by creating prosocial bonds through the use of psychedelics in ritual

• Contributing to the development of music, storytelling, and religion—some of the very traits that make us distinctly human

“Depatterning” Could Save the World

During Pollan’s research, he found that many experts involved in studying psychedelics have eventually shifted their emphasis from the treatment of individuals to the potential for the treatment of society as a whole. He explains that this is because the benefits of psychedelics may contribute to greater empathy, a deeper sense of connection with others, and a reconnection to nature. On this last point, many argue this could be a key to solving the growing environmental crisis.

(Shortform note: A 2019 study examined the correlation between psychedelic use and “nature relatedness” and found a positive association. They found an increase in nature relatedness after a single psychedelic session that persisted for two years after that use, and noted a “strong relationship” between the amount of lifetime use of psychedelics and nature relatedness.)

As we saw in the 1960s, psychedelics can also be disruptive to society. They can cause a shift in perspective that has the potential to subvert power structures, undermine established social institutions, and dissolve boundaries—such as those between the body and mind, the spiritual and material, and healer and patient. But, Pollan asks, are some of those disruptions exactly what we need in society right now? He and other scholars suggest that the timing of this psychedelic renaissance is no coincidence.

Ethnobotanist Giorgio Samorini says that psychedelic experiences disrupt our deeply ingrained patterns of thought and allow us to develop new creative ways of thinking. He calls this “depatterning” and says when societies are in rapid states of change or high-challenge situations, this ability to think in novel ways is crucial for adaptation and survival. So he concludes that psychedelics can be a tool for survival that humans turn to during specific time periods, such as when they’re facing challenges that need out-of-the-box thinking.

Pollan suggests that humanity as a whole is presently facing such a crisis, calling for a widespread depatterning. The enthusiasm around psychedelics in the 1960s may have been the first signs of this call to action. And of course, when there’s any movement toward social change, the established powers will attempt to stop it, to preserve the existing institutions and hierarchies. Pollan explains that we saw this happen with the ban on psychedelics in the 1970s, and we see it with the continued resistance today. This is why Pollan believes we must, as a society, “change our minds” about psychedelics, by making them widely accessible for use in mental health care.

Psychedelics Could Help Create a More Just and Equitable World

The anthology Psychedelic Justice: Toward a Diverse and Equitable Psychedelic Culture addresses ways that psychedelics might contribute to a more just and equitable world. Essays in the book suggest that social justice advocates today may be unintentionally creating more division by focusing on so many different issues of inequality as though they were separate phenomena. The complexities involved with many intersecting dimensions of inequality in the 21st century may require a novel approach, and the book argues that psychedelics could offer that.

It hearkens back to the counterculture movement of the 1960s, pointing out that prominent figures in that movement recognized the value of psychedelics as being in the potential to change minds. This reinforces the premise that Pollan has embedded in the title of the book: How to Change Your Mind.

So, the collection of essays in this book suggests that rather than simply trying to fight every systemic issue at the level of policy, we should be confronting the root of the issue: the way people think. And psychedelics could help to change the attitudes that created the systems of inequality in the first place. This could address issues like sexism, patriarchy, homophobia, and binary thinking that harm individuals.

The book argues, overall, that we should be working to integrate psychedelics into society as a whole, and it offers some guidance on how to do that while respecting indigenous communities and mitigating the potential risks and dangers.