Leiden (Netherlands), Since I was young I have been intrigued by altered states of consciousness, such as out-of-body experiences, paranormal phenomena and religious visions. I studied psychology and neuroscience to better understand how these experiences arise. And in my scientific career I have focused on the question of why some people are more likely to have these experiences than others.
Naturally, when I discovered psychedelic science a couple of years ago, this field also piqued my academic interest. This was an opportunity to study people who had a psychedelic experience and who claimed to have glimpsed ultimate reality. I started researching psychedelic experiences at Leiden University and founded the PRSM laboratory, a group of scientists from different academic backgrounds who study psychedelic, religious, spiritual and mystical experiences.
I was initially excited by the mind-transforming potential of psychedelics. These substances, when administered correctly, appear to be able to improve people's physical and mental well-being. They also increase feelings of connection and concern for the environment. Psychedelic therapy appeared to offer great potential for treating a wide variety of disorders, including depression, anxiety, addiction, and post-traumatic stress disorder. This enthusiasm for the potentially transformative effects of psychedelics was reflected in the positive media attention on this topic over the past few years. Michael Pollan, American author and journalist, has brought psychedelics to an audience of millions with his book and his Netflix documentary.
However, my initial optimism about psychedelics and their potential has turned into skepticism about the science behind much of the media hype. This is due to a closer examination of the empirical evidence. Yes, at first glance it seems that psychedelic therapy can cure mental illness. But if we look closer, the story is not so simple.
The main reason? Empirical evidence on the effectiveness and working mechanisms underlying psychedelic therapy is far from clear. Two issues
I wrote a critical review article with my colleague Eiko Fried in which we listed the problems with current clinical trials of psychedelic therapy. The main concern is called the "blind breaking problem." In studies of psychedelics, patients easily discover whether they have been randomly assigned to the psychedelic or placebo group, simply because of the profound mind-altering effects of psychedelic substances.
In reality, this breaking of the shutter may result in a placebo effect in patients in the psychedelic group: they finally receive the treatment they expected and begin to feel better. But it can also cause frustration and disappointment in patients assigned to the control group. They were hoping for a miracle cure, but now they discover that they will have to spend six hours taking a placebo pill with their therapist. As a result, any difference in therapeutic outcomes between the psychedelic and placebo groups is largely due to these effects. placebo and nocebo. (A nocebo effect is when a harmless treatment causes side effects or worsening of symptoms because the person believes they may occur or expects them to occur.)
Knowing who got what also affects therapists, who may be motivated to get more out of the therapy session if their patient got the “real deal.” And this problem is impossible to control in so-called randomized controlled trials, which remain the gold standard for evaluating the effectiveness of drugs and treatments.
Additionally, non-clinical research on psychedelics faces problems. You may remember the graph of a brain on psilocybin compared to one on placebo (see below). Psilocybin increases connections between different areas of the brain, which is represented by a colorful variety of connecting lines. This is known as the “entropic brain hypothesis.” Psychedelics make your brain more flexible, so that it returns to a child-like state of openness, newness, and surprise. In turn, this mechanism has been hypothesized to underlie the effectiveness of psychedelic therapy: by “freeing the brain,” psychedelics can change ingrained, maladaptive patterns and behaviors. However, it turns out that the picture is much more complicated than that.
Psychedelics constrict blood vessels in the body and brain and this causes problems in measuring brain signals with MRI machines.
The entropic brain graph may simply reflect the fact that blood flow in the brain is dramatically altered under psilocybin. Furthermore, it's far from clear what exactly entropy means, much less how it can be measured in the brain. A recent study on psilocybin, which has not yet been peer-reviewed, found that only four of 12 entropy measures could be replicated, which casts further doubt on how applicable this mechanism of action is.
Although the story that psychedelics free the mind is compelling, it still does not square well with the available empirical evidence.
These are just two examples that illustrate why it is important to be really cautious when evaluating empirical studies in psychedelic science. Don't take the findings at face value, but ask yourself the question: is the story too good or too simple to be true? Personally, I've developed a fair amount of skepticism when it comes to psychedelic science. I'm still intrigued by the potential of psychedelics. They offer excellent tools for studying changes in consciousness. However, it is too early to draw definitive conclusions about its mechanisms of operation or its therapeutic potential. To do this, we need more research. And I'm excited to contribute to that effort. (The conversation) SCY
SCY
Naturally, when I discovered psychedelic science a couple of years ago, this field also piqued my academic interest. This was an opportunity to study people who had a psychedelic experience and who claimed to have glimpsed ultimate reality. I started researching psychedelic experiences at Leiden University and founded the PRSM laboratory, a group of scientists from different academic backgrounds who study psychedelic, religious, spiritual and mystical experiences.
I was initially excited by the mind-transforming potential of psychedelics. These substances, when administered correctly, appear to be able to improve people's physical and mental well-being. They also increase feelings of connection and concern for the environment. Psychedelic therapy appeared to offer great potential for treating a wide variety of disorders, including depression, anxiety, addiction, and post-traumatic stress disorder. This enthusiasm for the potentially transformative effects of psychedelics was reflected in the positive media attention on this topic over the past few years. Michael Pollan, American author and journalist, has brought psychedelics to an audience of millions with his book and his Netflix documentary.
However, my initial optimism about psychedelics and their potential has turned into skepticism about the science behind much of the media hype. This is due to a closer examination of the empirical evidence. Yes, at first glance it seems that psychedelic therapy can cure mental illness. But if we look closer, the story is not so simple.
The main reason? Empirical evidence on the effectiveness and working mechanisms underlying psychedelic therapy is far from clear. Two issues
I wrote a critical review article with my colleague Eiko Fried in which we listed the problems with current clinical trials of psychedelic therapy. The main concern is called the "blind breaking problem." In studies of psychedelics, patients easily discover whether they have been randomly assigned to the psychedelic or placebo group, simply because of the profound mind-altering effects of psychedelic substances.
In reality, this breaking of the shutter may result in a placebo effect in patients in the psychedelic group: they finally receive the treatment they expected and begin to feel better. But it can also cause frustration and disappointment in patients assigned to the control group. They were hoping for a miracle cure, but now they discover that they will have to spend six hours taking a placebo pill with their therapist. As a result, any difference in therapeutic outcomes between the psychedelic and placebo groups is largely due to these effects. placebo and nocebo. (A nocebo effect is when a harmless treatment causes side effects or worsening of symptoms because the person believes they may occur or expects them to occur.)
Knowing who got what also affects therapists, who may be motivated to get more out of the therapy session if their patient got the “real deal.” And this problem is impossible to control in so-called randomized controlled trials, which remain the gold standard for evaluating the effectiveness of drugs and treatments.
Additionally, non-clinical research on psychedelics faces problems. You may remember the graph of a brain on psilocybin compared to one on placebo (see below). Psilocybin increases connections between different areas of the brain, which is represented by a colorful variety of connecting lines. This is known as the “entropic brain hypothesis.” Psychedelics make your brain more flexible, so that it returns to a child-like state of openness, newness, and surprise. In turn, this mechanism has been hypothesized to underlie the effectiveness of psychedelic therapy: by “freeing the brain,” psychedelics can change ingrained, maladaptive patterns and behaviors. However, it turns out that the picture is much more complicated than that.
Psychedelics constrict blood vessels in the body and brain and this causes problems in measuring brain signals with MRI machines.
The entropic brain graph may simply reflect the fact that blood flow in the brain is dramatically altered under psilocybin. Furthermore, it's far from clear what exactly entropy means, much less how it can be measured in the brain. A recent study on psilocybin, which has not yet been peer-reviewed, found that only four of 12 entropy measures could be replicated, which casts further doubt on how applicable this mechanism of action is.
Although the story that psychedelics free the mind is compelling, it still does not square well with the available empirical evidence.
These are just two examples that illustrate why it is important to be really cautious when evaluating empirical studies in psychedelic science. Don't take the findings at face value, but ask yourself the question: is the story too good or too simple to be true? Personally, I've developed a fair amount of skepticism when it comes to psychedelic science. I'm still intrigued by the potential of psychedelics. They offer excellent tools for studying changes in consciousness. However, it is too early to draw definitive conclusions about its mechanisms of operation or its therapeutic potential. To do this, we need more research. And I'm excited to contribute to that effort. (The conversation) SCY
SCY
