- Welcome everyone to Wednesday Nite @ the Lab. I'm Tom Zinnen. I work at the University of Wisconsin-Madison Biotechnology Center. I also work for the Division of Extension, Wisconsin 4-H. And on behalf of those folks and our other co-organizers, PBS Wisconsin, the Wisconsin Alumni Association, and the UW-Madison Science Alliance, thanks again for coming to Wednesday Nite @ the Lab. We do this every Wednesday night, 50 times a year. Tonight it's my pleasure to introduce to you Cody Wenthur. He's an assistant professor in the School of Pharmacy here. He was born in Cedarburg, Wisconsin and went to Cedarburg High School. Then he went to Purdue University to get his doctorate in pharmacy, and then went to Vanderbilt University to get his PhD in pharmacology. 

 He post doc'ed at the Scripps Research Institute in La Jolla, California. Tonight, he's gonna speak with us about his research on psychedelics and how they're a catalyst for change in the area of mental health. Please join me in welcoming Cody Wenthur to Wednesday Nite @ the Lab. - Thank you very much, Tom, for that introduction. And thank you for the opportunity to give this talk. I'm excited to speak to you about psychedelics and mental health, but in order or for us to understand what I'm talking about throughout this talk, the first question we need to answer is, what are psychedelics? And the first place that we see the word psychedelic come up is in a quote by Humphry Osmond from 1957, where he says, "To fathom hell or soar angelic, just take a pinch of psychedelic. " And this was a new word penned at that time. And it's derived from two Greek roots, psyche, meaning mind or delos to make manifest. So together, psychedelic means to make the mind manifest. Because one of the things that these compound seem to do is enhance the salience of thoughts and to bring them to the surface in ways that might not otherwise be obvious. 

 Now, there is a pharmacological definition of what a psychedelic is, and here on this plot we can see compounds like LSD, psilocybin, and dimethyltryptamine, which are formally psychedelics. But in this talk, we'll also be talking about compounds like ketamine and MDMA, which are dissociatives or empathogens, respectively. And the reason that we're going to see some of these compounds that aren't formally psychedelics being discussed in this talk, is because in modern clinical usage, some of the same approaches have been applied to these compounds that are also being applied to the classical psychedelics like LSD and psilocybin. So we have both a pharmacological definition, but then you'll often see in literature and in the public parlance, a little bit looser definition that includes some of these associated compounds. And although we saw the word psychedelic cropping up for the first time in the mid 20th century, the history of these compound themselves actually goes back much, much longer. And although the timeline shown on this slide is encompassing a swath of approximately the last 80 years, human use of psychedelics is actually ancient and prehistorical, where 99% of human experience with compounds like psilocybin, which is in magic mushrooms and DMT, which is in ayahuasca, actually occur for more than 6,000 years. So that's 99% of our experience is not encompassed on this timeline. That being said, the 20th century has been an era of proliferation for new psychedelic compounds, including the first synthesis of naturally occurring compounds, like mescaline. First time they were synthesized in the lab, as well as the synthesis of new compounds, like LSD, which aren't naturally occurring, but are derived from natural precursors. And then as we enter the 21st century, we see the application of these compounds clinically. 

 And indeed, this 21st century application is a resurgence of what we saw in the middle of the 20th century, where there was a great deal of interest by psychiatrists in the clinical application of these compounds that were branded psychedelics, but due to schedule I placement in the Controlled Substances Act, which is the most restrictive schedule that says both these compounds have a risk of abuse and also no accepted medical use, there was a period of diminished research on their clinical applications. Further on in this talk, we'll see the ways in which we're currently re-exploring the potential in some of the clinical outcomes that have been seen to date. In the second half of the talk title was mental health. So we talked about what psychedelics are. Let's also talk about what the current status of mental health is in the United States of America today. And presently, mental health in the United States faces some significant challenges. There are nearly 50 million Americans, or almost 20% of American adults, that experienced a mental illness in 2019. And almost 5% of adults report having serious thoughts of suicide. This is a number that's increased every year since 2011. Likewise in youth populations, 15% are experiencing a major depressive episode in the past year, and access to mental health treatment remains a serious challenge for many U. 

S. adults. If we look at other features contributing to negative mental health, like alcoholism and drug overdose, we see there's a really staggering number of excess deaths that are occurring because of these outcomes. That is, there are almost 850,000 people that have died from a drug overdose since 1999 in the United States. And these numbers continue to go up in recent years, with 28. 5% increase in the number of drug overdose deaths recently. In Wisconsin, we see similar trends, where alcohol-attributable deaths over time have been increasing in recent years, and we have about 3,000 deaths. Likewise, there are about 8,000 deaths due to all drugs in the state of Wisconsin annually. We mentioned suicide as a problem in the United States, and this slide gives us some further information about the serious issue of suicide. There are about 50,000 people that have died of suicide in 2019 and recent years. 

 That's one death every 11 minutes. And this is now the 10th leading cause of death in the United States, after undergoing a 40% increase since 1999. Although people often think of suicide as being a problem that's distant from them, the reality is that almost every person probably knows someone who has considered suicide. And there is an elevation in suicide rates in jobs like mining, quarrying, oil and gas extraction, construction, automotive repair, forestry, farming, and others that form the backbone of our economy and our society, which is a giant problem across the United States, but especially here in Wisconsin, where those jobs and those individuals make up a large percentage of our population. These deaths due to drug overdose, alcoholism, and suicide are often called deaths of despair. And in the data, we can see that the United States is currently an outlier when it comes to these deaths of despair. In comparison to other countries like Germany, France, Sweden, Canada, the United Kingdom, and Australia, there have been many more deaths of despair in the United States, particularly among white non-Hispanic adults, than in these comparator countries since the turn of the 21st century. And these deaths are especially elevated in individuals with no college degree, both individuals with white and Black identities. And so there are many working families who are struggling with alcohol, drug abuse, and suicidality that are in need of some improvements, in need of some new ideas about how to reconnect them to their communities, how to reinvigorate their lives, and how to help them out of this mental health crisis. Another group that's been disproportionately impacted by these negative mental health outcomes are our veterans. 

 And the number of veterans with PTSD, or post traumatic stress disorder, is certainly higher than the average population, but it does vary somewhat from service era to service era. We can see somewhere between 12-15% of individuals that were in the Gulf War and the Vietnam War having been diagnosed with PTSD. Likewise, the rate of suicide in our veterans is about twice as high among veterans as in the general population. Because of this, there's been a special interest in uptake in the use of psychedelic-assisted psychotherapy approaches, such as the ones we'll be talking about today, for treatment of veterans' populations. And finally, the last word on the state of mental health that we'll talk about is access. And this map shows us health professional shortage areas across the United States, and you can see in the dark blue, these are areas where the whole county is a shortage area, in the medium blue, where part of the county is a shortage area, and in the light blue, those areas where none of the county is a shortage area. And most of the United States is considered a health professional shortage area. If we look at Wisconsin and look at shortage areas for mental health care, you can see a large majority of our counties fall within this shortage area definition. So not only do we have a problem with increasing burdens of negative mental health outcomes, we also have a big challenge to meet that, in terms of bringing mental health care to the folks that need it most. With that understanding of a little bit about where psychedelics come from and what the challenges that we're trying to meet, the next question we want to talk about is how might psychedelics actually act on the brain in order to affect changes in mental health? And the first thing we wanna know about psychedelics is that they are agonists at the serotonin 2A receptor. 

 This is a particular protein in your brain that normally responds to the neurotransmitter serotonin, which is a common target for other antidepressant medications, like Prozac. These compounds, psychedelics, as you can see in the structures on the slide, actually often bear a structural similarity to serotonin, and so it's perhaps not surprising that they're binding to some of the same places that these natural neurotransmitters bind. That being said, in addition to the serotonin 2A receptor, the psychedelics have several other sites of action. They have sites of action at other serotonin receptors, as well as often at dopamine receptors, and others in the brain. So the question is, if serotonin is normally binding to these receptors and psychedelics are binding to these receptors, why are they having such a profoundly different effect on our perception than serotonin? Psychedelics induce hallucinations and a completely altered sense of perception, while serotonin doesn't. And the reasons we think that serotonin doesn't affect these changes, but psychedelics do, is that there may be something called biased agonism happening. That is, when you bind to these receptors, when a compound binds to these receptors, it can elicit not just one outcome, but one of several different outcomes. And we can see here, from the comparison of lisuride, a non-psychedelic compound, and LSD, which is a classical psychedelic drug. They're very structurally similar, and indeed, they both do bind to that serotonin 2A receptor. But evidence has shown that they may elicit different downstream outcomes. 

 And in the plot that's shown on this slide, we're looking at the expression of different genes occurring after these drugs have been administered, and you can see a cluster of outcomes for those compounds that are psychedelic in the black. So mescaline is a psychedelic, psilocybin, LSD, DOI. These are all psychedelic compounds, and they're having a similar type of effect on these downstream genetic outcomes. Whereas the non-psychedelic compounds that are structurally related have a different profile, giving us some indication that these compounds are actually having a different effect at the molecular level. Another important thing to know about psychedelics that's come out in recent work by David Olson and other groups, is that psychedelics seem to promote actual restructuring of neurons. So unlike other cells in our body, which may turn over on average as often as every seven years, neurons don't tend to turn over all that often in our life. There are some areas of the brain where we do have new neuronal growth, but generally, neurons are with you for the vast majority of your life. And so change in the brain is often manifest through the restructuring of these neurons. Each of them are making connections with other neurons, which is how the brain is talking to itself at these functional synapses. And when you form new structures and new synapses, this is often a correlate of memory and of new learning. 

 And when compounds like DOI or DMT or LSD have been administered to cultured neurons, those are neurons that are growing in a dish. What has been observed is that new neural outgrowth is occurring. That is, new branches are coming off of that neuron, making new opportunities to connect with other neurons. Likewise, it's been seen that there's formation of new spines, which are the structural components on which synapses form, and that we see expression of key proteins like PSD-95 and VGLUT1, that are supporting the expression of new functional synapses. So psychedelics are inducing new structural and functional plasticity in the brain. The other fascinating thing about the way that psychedelics act in the brain is that they change the way the brain talks to itself on a larger level. There are networks, like the default mode network, the executive control network, the visual network, the salience network, and so forth, where there are certain regions of the brain that are likely to communicate with one another more frequently than they are to communicate with other regions of the brain, and these form sort of standing groups of areas in the brain that have common communication patterns. And on the right-hand side of this slide, what we see are two network connectivity diagrams. One of these is the diagram underneath the placebo condition. And in this diagram, those networks that are standing are colored similarly to one another. 

 So in the purple dots, for example, that represents one standing network. Whereas the red dots represent another standing network, and the lines between them are showing the strength of connection between each of these regions of the brain. And what we see from the placebo plot is that as we expect, if there are these standing networks, most of the communication is happening within the same network, with relatively fewer crossings between networks. But following the administration of psilocybin, during the acute psychedelic experience, we see far more connections between these networks, a sort of anarchic breakdown of the hierarchical structure of the brain. So the way that it's normally communicating with itself is kind of disintegrated underneath this experience, and this has been proposed as one of the reasons that people often have, for example, synesthetic effects, where they can taste sounds, for example, underneath the influence of classical psychedelics. But this also might have implications for their potential therapeutic activity. The last thing to note about the psychedelic actions on the brain of course, is the experience itself, where psychedelics are most known for introducing an altered state of consciousness. People are having alterations of their visual processing, with visual hallucinations. They may have those audio-visual synesthesia. They often have very vivid imagery. 

 They think there's high levels of insight, and there's changed meanings to the things in their environment. Sometimes people will report disembodiment or impaired control or cognition. Frequently, there are experiences of unity and loss of the sense of a personal ego. And while all of these things are fairly difficult to reduce to a single dimension or to quantify, there are clinical scales available, things like the 5-Dimension Altered States of Consciousness Questionnaire that have been used to reproducibly show that specific psychedelics have specific and dose-dependent changes across these dimensions of the altered state of consciousness. And by using these different scales, we can begin to understand, and importantly, can begin to reproducibly introduce an altered state of consciousness in ways that isn't possible in the absence of psychedelics, which may make them a uniquely powerful tool for influencing mental health. Together, these changes in molecular and cellular signaling, the changes in structural plasticity, the changes in network connectivity, and then these changes in perception and meaning, seem to come together to form a catalyst for long-term change, following the application of psychedelics. But that demands the question, although these drugs are doing all these interesting and unique things in the brain, is a drug really enough to produce long-term changes in mental health, all on its own? And as currently used, psychedelics are not following this model. Psychedelics are embedded within a psychotherapeutic component. That is, in addition to getting the drug in clinical trials using psychedelics, people are also getting psychotherapy. And looking at the slide we have here, there's one model of how psychedelics could induce long-term improvements in mental health, together with psychotherapy. 

 Thinking back to that network diagram and those connections between different sections of the brain, here we have a simplified version of that plot. And we can conceptualize someone with depression, for example, is where their connections between certain areas of the brain are stronger than they otherwise would be because of overuse of that circuit. There's a relatively well-trialed idea in neuroscience that those neurons that fire together wire together, which means that if you use a circuit often in enough, you'll actually get those physical changes where they have stronger connections between them. This can also result in not just physical changes in the brain, but clearly, those behavioral changes that might put you in the type of rut that someone would describe when they're having a depressive episode. And what psychedelics might do, through those molecular actions, is to acutely weaken the old connections to help form new connections between those areas of the brain that aren't always talking to one another and thus, potentially allow cognitive escape. If you think about a snowy field, the first person to walk across that field has many choices of how to get from point A to point B. But after they've crossed it, the next person is probably more likely to follow in their tracks because it's simpler. And it's not until there's a new snowfall that those old paths will go away. And so some people have conceptualized psychedelics as kind of shaking up the snow globe of the brain and allowing new connections and new paths to be formed. But that psychedelic-assisted psychotherapy component is the key point toward understanding how we could actually use this in a therapeutic approach, because there's nothing that says that just shaking up the snow globe and forming new paths should necessarily cause your behavior to be any better than it was in the past. 

 And indeed, it's been conceived that the role of the mental state in psychedelics just puts you into a pivotal mental state where you're poised for change. Things can get better, they could get worse, and that you need some influence of psychotherapy and support in order for those new patterns of behavior and improved patterns of behavior to take hold. Because of this, others who have been doing clinical trials incorporate very rigorous structures around the psychotherapy component. In this example, we're looking at a training session and therapeutic sessions from the MDMA or ecstasy-assisted psychotherapy trial for PTSD. And each of these colored blocks represents a visit of the participant in that trial. There are three times that the individuals get the drug, but overall, there are 16 times that they come in. This includes preparation sessions to allow the person to understand what to expect when they're receiving the drug, and it also includes integration sessions that help people process the insights that come up during the MDMA experience itself. As part of this, there are two guides or therapists in the room together with the individual while they're having the experience, and also therapeutic support throughout the full process. So we can see here that there's much more to this therapy than just the drug itself. And in addition to those therapeutic components, there's also a unique set and setting. 

 That is, the preparation and integration sessions are designed to put individuals in a calm mindset, to be accepting of insights, and to be willing to work with the material that comes up during a psychedelic session. There's also a unique built environment with comfortable furniture, soft lighting, music tracks, for example, that help people look inward to help support the psychedelic experience itself. So with all of this effort being put into generating an effective psychedelic experience, and then following that psychedelic experience up with therapy and attempts to understand the insights generated, do we have evidence that this actually could work? And all the data I'm about to show you in this section was generated by other researchers, and you'll see later how my lab is trying to work on building from this exciting data set. So some of the first insights that we had into potential new therapies for the treatment of depression come from ketamine treatments. Ketamine, as we saw very early in this talk, is not a classical psychedelic. It's a dissociative compound, but it has been used in ketamine-assisted psychotherapy, and is also interestingly used as a therapy on its own in the absence of psychotherapy that nevertheless does seem to act in some ways by altering the plasticity of the brain. And here, we're going to look at some data for its use in treatment-resistant depression and reductions in suicidal ideation. On the left-hand plot, what we're looking at is a comparison between ketamine and placebo at a couple different time points. The studies in the top half are looking at the effect of ketamine on treatment-resistant depression 24 hours after being administered, and those in the bottom half are looking seven days after the ketamine has been administered. And the way that these data are shown is that anything to the right of the red line that I'm showing you there, indicates that ketamine had a greater effect than that of placebo. 

 Anything to the left indicates that the placebo performed better. And we can see across all of these time points and all of these studies that placebo overall is having a positive effect in reduction of treatment-resistant depression symptoms. Likewise, in suicidal ideation, if we look at several trials with intravenous ketamine or trials with an intranasal form of S-ketamine, a single enantiomer, that likewise, we see the effect is favoring ketamine. If we look at a similar type of data set for classical psychedelic compounds, we can see that in short-term effects, which are on the top, medium-term effects, which are in the middle, and long-term effects, which are on the bottom, that these trials, relatively consistently, indicate that psychedelics are superior to placebo in reducing depressive symptoms and improving mood. And this does vary a bit from trial to trial and drug to drug. Here, we're seeing the compounds psilocybin, LSD, and the concoction ayahuasca, which includes DMT, all independently being studied. But when we look at the combined data, the all data, in every case throughout these time points, it appears that there is a more positive effect from the psychedelic than from placebo, which is a very encouraging sign. In a very recent phase two clinical trial using psilocybin for treatment-resistant depression, basically the biggest study of its kind to date, psilocybin at two different doses, either 10 or 25 milligrams, was compared to placebo. And overall in this study, we're looking at approximately 225 individuals. And with in comparison to placebo, what we see, especially at the 25 milligram dose, is a significant reduction in the depressive symptoms very quickly, only on day two, that's one day after the drug administration, that seemed to persist up through week six of treatment. 

 So with a single bout of psychedelic-assisted psychotherapy, we see both a rapid reduction in depressive symptoms, as well as a persistent effect over several weeks. This stands in contrast to some of our gold standard therapeutics for depression, like SSRIs, which may take six to eight weeks in order to show maximum efficacy in most patients, and indeed, which ultimately leave about 1/3 of patients untreated, even after three to four different attempts to use multiple types of antidepressant therapy. And so to see this type of effect in treatment-resistant depression, which are patients who have failed several of these other therapies, is quite encouraging. That being said, bigger studies are underway and definitely need to be confirmed in order to make psilocybin move toward FDA approval. A couple other areas where psilocybin has shown promise is in substance use disorders. So on this slide, we see psilocybin being used for alcohol use and for tobacco use. On the left-hand side, we're seeing a measure of the number of individuals engaging in drinking on any given day or on heavy drinking on any given day, following two doses of psilocybin in conjunction with psychotherapy. And we can see that after the first, and especially after the second dose, that there is a substantial reduction in the percentage of drinking days and heavy drinking days that persists out for several weeks afterwards. Likewise, in the context of tobacco use, after a single intervention with psilocybin-assisted psychotherapy, we see dramatic reductions in the number of cigarettes that are being smoked per day at 10 weeks. And for many patients in this data set, which is fairly small, only about 15 people, persistence through six months and even a year. 

 So these are very small data sets, definitely need to be followed up, but quite encouraging data that this could also be an effective approach in the context of substance use disorders. Next, we're gonna look at some data from a patient population that really set off excitement for the clinical use of psychedelics. And that is a patient population facing a very, very difficult situation. These were patients who were given end of life cancer diagnosis, a diagnosis that could be terminal. They may only have weeks or months to live. And in many of those patients, unsurprisingly, we see that they also have mental health challenges that crop up. They may actually get diagnosed with depression and anxiety as a result of being given this life-altering diagnosis and getting this extremely challenging information. And we do have palliative care approaches, certainly, for individuals with end of life cancer, but the number of interventions that are available to improve quality of life and to address those psychiatric consequences are not as good as we might hope. In this study, psilocybin again, was being given to individuals in conjunction with psychotherapy, and measures of anxiety, depression, quality of life, and death acceptance were all taken together, following the psychedelic experience. And on the left, we can see the results from the depression scale. 

 In this study, people either got a low, basically inactive dose, of psychedelic first and then a high dose second or vice versa. And we can see that after the first dose, those who got the high dose, that had the full psychedelic experience, had dramatic reductions in their depression scores. There was some effect of the low dose as well, but that was even significantly bumped further once they got the high dose in the second session. And we can see persistence of these antidepressant-like effects up through six months in this patient population. I've also added a line to this graph that shows the threshold for remission for these depression scores. And you can see that on average, actually, these patients met the threshold for remission, meaning they no longer met the criteria for a depression diagnosis after this experience. We can likewise see very strong increases in the overall quality of life in this patient population. The final trial we're going to look at is the use of MDMA, which is an empathogen or entactogen, that is also being given in conjunction with psychotherapy for severe PTSD. And on this slide, we're looking at a phase three trial, which is the trial that's immediately preceding submission to the FDA for approval. So the biggest type of clinical trial that we have prior to a drug entering the market. 

 And in this trial, what we're looking at is either psychotherapy alone or psychotherapy plus the use of MDMA. And in this trial, as we saw from the plot earlier with all the study visits, there were three drug sessions and again, 16 visits overall. And we're looking at reductions in the clinician-administered PTSD scale, which is the gold standard for diagnosis of PTSD. On the left, we can see superiority, where MDMA is added to the psychotherapy. Likewise, on the right, if we look at the Sheehan Disability scale, which is a tool that's looking at functional outcomes, like how well is your life going at work, at school, your social life? How well are you engaging with your family? We also see superiority of the MDMA-assisted psychotherapy and progressive improvements from session one, to two, to three. And perhaps most encouragingly of all, at the end of the study, when we looked at those individuals who either got the MDMA or did not, 2/3 of the MDMA group no longer met the criteria for PTSD compared with about 30% who got the placebo plus psychotherapy. So in about 1/3 of people, psychotherapy worked, but in 2/3, we saw a complete loss of diagnostic criteria for those who also got PTSD. Notably, 33% or 1/3 of the MDMA group met the criteria for remission, whereas only 5% of the placebo group met those criteria. So a substantial increase through the use of a psychoactive compound to modify the outcomes of the psychotherapy itself. So those are some of the good things that we're seeing, the encouraging signs that this might be helpful. 

 But you might be asking yourself, what risks are associated with this approach? All drugs come with risks. The word for drug, the initial word pharmacon, again from the Greek, denotes both therapy, but also poison, and all drugs have both benefits and risks. It all depends on getting the right drug to the right patient in the right dose at the right time. And these are some of the side effects that we see in psychedelic clinical trials. Most individuals will experience a transient increase in their heart rate and blood pressure for about the first 60-90 minutes after they get the psychedelic. Also, seeing headache is fairly common. This is generally treated with a standard dose of Tylenol. Nausea and vomiting are seen in some individuals. And then MDMA specifically seems to induce muscle tightness, can decrease appetite, have sweating and dizziness. In the context of psychoactive side effects, about less than 1% of individuals from the trials that have been reported so far report potentially risky disorientation or lingering or delayed psychological effects. 

 But when we compare psychedelics to other classes of psychoactive compounds, using a measure of the risk of harm to the user themself and the harm to others, here we can see that, for example, alcohol has a relatively high risk of harm to the user, as well as significant risk of harm to others. Whereas compounds like LSD and psychoactive mushrooms have much lower levels of risk of harm to the user and harm to others. But clinical trials are different than real world use, and one of the things that's often reported by people who use psychedelics in a recreational or non-medically supervised context is that they can have a bad trip, a very anxiety-inducing and provoking experience. And they may in fact, report that they're a danger to themselves or others. And when we look at surveys asking people about their worst bad trip, we do see higher rates of these negative outcomes outside that controlled context of clinical trials and without that built-in psychotherapeutic support. So about 11% report putting themselves or others at risk. 2. 5% behave in a physically aggressive manner. And somewhere around the same percentage need to get medical help. Also, 7. 

5% of people reported seeking treatment for psychological symptoms associated with their negative trip, and relatively small numbers of individuals, although still notable, has onset of psychotic, severe symptoms as well as attempted suicide. So the potential for negative outcomes is there, but you'll note for certain, that these outcomes are much higher in this case, of unsupervised medical use than what's currently being reported in the clinical trials. The risk factors that have been shown to support this potential dangerous behavior outside of the context of clinical trials are use by individuals with psychotic disorder, relative inexperience with the drug, having poor information about what the drug is likely to do, by combining psychedelics with other drugs or with alcohol, and by putting themselves in risky situations and using with unknown or untrusted individuals. There are harm reduction options available for people who are using psychedelics outside medical context, such as the Zendo Project and the Fireside Project. So with all this background, all this wonderful work that's been done by other researchers in the field, as well as all the information we've learned from Indigenous cultures, their elders, and their sacred practices. What is my lab doing and how are we involved in this area of study? One of the things that we're doing is assessing combinatorial contributions to ketamine's antidepressant effects. Ketamine has many metabolites, as you can see on the left side of this slide. That means it's broken down into a bunch of different compounds inside the body. And we're using techniques such as development of antibodies against selective compounds in order to assess the effects of each of these independently and together, and also to map the areas in the brain where ketamine and its metabolites are having these effects. Unfortunately, we've got a lot of projects, so that's all you're gonna hear about that project. 

 Another one that is very exciting to me, but we don't have the full answers on yet, is projects in human subjects, where we're assessing the psychedelic experience and its therapeutic causality. Basically asking the question, is the psychedelic experience that altered state of consciousness, and particularly the memory of it, necessary in order for individuals to get better, or is it possible that people could get better through the molecular effects alone and not having any access to the memory of that altered state of perception or the potential insights that they may report, when otherwise coming out of a psychedelic experience? It's a study I'm very excited about, but stay tuned. The last two types of work that we're doing are in a similar domain, and we're gonna look much more in depth at a preclinical project in rodents and a clinical project with human subjects and community-associated outreach. And both of these projects are related to the idea of relating stress self-identity and set and setting, and how those interact in psychedelic-assisted psychotherapies. Classically, as I alluded to the approach with psychedelic-assisted psychotherapy, has been to have people be as calm as possible during the experience and have them ready and prepared to understand what's happening. Certainly, we think that preparation is absolutely essential, but we wonder whether or not there was a negative or positive role biologically of the stress response, and whether that's different than the apparent negative psychological role of the stress and anxiety response that some people indicate. And in the first study, we're looking at again, those markers of biological stress. So it's been appreciated for several years now, including work that we're seeing here from others, Franz Vollenweider's group, as well as Leah Roseman, that during the transient period of altered psychoactive perception and altered activity in the brain, that we do see elevations in the stress-associated hormone, cortisol, at about that 150-minute mark, which is also where the so-called peak psychedelic experience is also happening. It seems to resolve by about the 300 minutes, but that increase in cortisol is also concurrent or happening at the same time as increases in what's called anxious ego dissolution, or people being worried about the fact that they're seeming to lose connection with their identity. And we can see here, going from the left to the right, that with increasing doses of the psilocybin, from very low dose to low dose, to medium dose, to high dose, that there is a dose-dependent effect, both for the cortisol release and for the anxious ego dissolution. 

 And this has been used to suggest that stress during the time of administration is negative because on the bottom right plots, what we see is that the more anxious ego dissolution that was reported, the less change there was in depressive symptoms as measured by this scale. So those individuals who are on the high side of this scale had greater reductions in their depressive symptoms. But those who are on the low side of the scale had lesser effects. And you'll note that those who have higher dread of ego dissolution tend to have the lower effects. But because we're having both a biological effect and a psychological effect together, it's hard to disentangle, which may actually be responsible for blocking the therapeutic outcome or for modifying that therapeutic outcome. And so we are using rodent models to look at the relationship between the stress-associated hormone. And in this data, we see that like in humans, psilocybin can induce a transient increase in stress-associated hormones. We saw cortisol in humans; the analog in mice is corticosterone, and on the right-hand side, we can see a transient increase in that corticosterone that resolves. And on the left-hand panel, what we're looking at is a proxy measure of hallucinogenic-like activity, called the head twitch measure in mice, and we can see that these animals are having this biological marker of hallucinogenic-like activity that's basically coterminous with this spike in corticosterone. But the interesting observation we've found is that using a measure called the open field test, where mice are more likely to stay near the edge because they feel safe rather than move into the center of a wide-open arena, we see that psilocybin's acute effects at this 15-minute time point are inversely correlated with their post-acute effects in mice. 

 That is, at the time we have this high corticosterone, the mice are anxious. They don't seem to want to enter the center of the arena, and we have a dose-dependent response there. But at four hours, by the time psilocybin has left the system of these mice, actually we see the opposite, that at the higher doses of psilocybin, they now have a seeming rebound effect, where they're more willing to spend time in the center. And using another measure of potential anxiety-like behavior, we see that at that very high dose, the three milligram per kilogram dose, that if we put the mice in an environment where they're motivated to eat a sugary pellet, but it's also brightly lit, it's an open field, and they may not normally want to enter that unusual environment, that those animals that were treated with psilocybin actually spend less time until they approach and begin to eat that pellet, than animals that didn't receive the psilocybin, potentially indicating that at these high doses, there is a real anxiolytic-like or anxiety-reducing effect. And because it's at those high doses we saw the spike of corticosterone, this indicates that biologically, having that stress response may not inherently be negative. But what we also see is that if we modify the response of the stress in these animals long-term, that this effect can be blunted. So when we look at anxiety-like effects one week after, and we have mice that either had no change in their corticosterone levels, or where we elevated the corticosterone, thus simulating an ongoing stress-like response for a long period of time, for that full week, we see something very different. So in the animals that didn't have a manipulated stress response, they just had that transient peak, the psilocybin tended to have an anxiolytic-like effect up to a week later, which is similar to the types of observations that have been reported in people. But in a situation that mimics chronic, unresolved stress, the psilocybin actually seemed to have a negative effect, relative to those animals that didn't get the psychedelic, indicating that unresolved stress at the biological level may in fact, be a mechanism by which those people who had strong psychological stress could be influencing their negative outcomes. The other study that I want to talk about is a human trial, where we're looking at the relationship of set and setting, with representation and generalizability. 

 It's been noted that ethnic and racial representation in psychedelic studies is not representative of the population as a whole. So whereas the United States in general has approximately 40% people of color, psychedelic clinical trials have only about 11% people of color. And if we don't have a representative sample in our trials, it's harder to make the claim that this therapeutic will be effective for everyone who comes to use it in the event that it is approved. And for this reason, we're interested in understanding the relationship between self-identity and therapeutic outcomes. Earlier, we talked about how set and setting are a part of these clinical trials. And the reason we think it's worth understanding the implications of self-identity is because if we think that the set and setting are responsible for influencing the psychedelic efficacy and that self-identity influences the mindset and setting, then the logical output is that self-identity itself can influence psychedelic treatment efficacy through this lens. And an example of this that I like to share is that in the psychedelic study room, the people who put the room together had the choice of what art to put on the walls. For example, you can put up a medicine wheel or you could put up a cross. And obviously, depending on your own self-identity, your religion particularly, or your spiritual background, you're going to have a very different reaction to each of these two items. And those elements of your self-identity may directly influence or be mitigating your response to the art, but other elements of your self-identity, like your race or your connection to the land might be likewise influencing your response overall. 

 And so we're conceptualizing that set and setting might actually act as a therapeutic modifier, where if your self-identity is congruent to the set and setting, you're likely to pass through and have a therapeutic effect. And given that most of our trials to date have had predominantly white subjects, we might imagine that the set and settings have sort of evolved to match and maximize therapeutic effects for the types of participants that we've already been enrolling, and the concern is that we might thus be minimizing or reducing therapeutic effects for people who don't share those same identities. In our project that's ongoing, we're using relationship to art objects as a starting point to try and develop a fit scale for this set and setting. Going back to our example of a choice of an art object, you can imagine that at a site here in Wisconsin, or at a site in Maryland, where we're running a psychedelic clinical trial, there could be two different pieces of art on the wall. Maybe here in Wisconsin, we have this cheese shop image and in Maryland, they have this crab picker image, and depending on a person's background, they could potentially have very different reactions to these two objects. If a person is from Maryland, they may report that their overall impression of the cheese shop image is less than that from someone from Wisconsin. And likewise, depending on the other elements of their self identity, it may be more or less connected to their sense of what it means to be their age, to have their gender, their own race, the locality they're at, and their concept of what the history of psychedelics is. And by gathering this information across many different individuals, what we're trying to do is quantify how well the set and setting fits individuals in current psychedelic clinical trial settings, where a person who has a very good or relatively good fit to the set and setting might be expected to have a stronger therapeutic effect than a person who has a more negative association with that set and setting. We can both use this potentially to quantify and harmonize data across clinical trial sites, but we can also use this to validate and permit patient choice in the setting, where a person with a background that may make them more receptive to this crab picker image would be able to have that image brought in and shown to them during the session, versus a person who is more receptive to this cheese shop image. And by doing that, what we hope to do is eliminate this hidden variable, this fit score, to maximize the benefit for all, that we have a flexible set and setting that people feel most comfortable with, minimizes their long-term stress and maximizes their therapeutic effect. 

 In our first pilot study with the Madison Psychedelic Society, we do see that when measuring perceived connectivity to the dosing room, across the dimensions of whether it connects to the local environment, the history of psilocybin, or to their own racial and ethnic identity, that those individuals with any identity other than non-Hispanic white actually did significantly report a lower connection to the dosing room, with regard to their own race. And what we're looking to do is to expand this beyond our local environment, to work with the Milwaukee Psychedelic Society as well as others across the country, in order to get a bigger sample set and help understand and generate this quantitative fit score. That covers it all for the type of work we're doing right now. But I also wanna say we're actively engaged in research and scholarship as part of this Transdisciplinary Center for Research and Psychoactive Substances, which has many other wonderful members from across campus, including folks doing the clinical trials that we talked about, but also looking into other elements of the history and cultural applications of psychedelics, all of whom are fantastic colleagues and I'm sure you'll hear from them more in the future if you follow this area. Likewise, I'm responsible for directing the training and education initiatives here at UW-Madison, including the first in the world Psychoactive Pharmaceutical Investigation masters program, and an associated capstone certificate program. In the event that these compounds are approved, we saw that there is already a challenge in delivery of mental health, and we're looking to generate the next generation of scientists, as well as to educate the next generation of healthcare providers on how we may potentially use these compounds and how we may improve them for future use. So overall, what did we learn from this talk? Unfortunately, hundreds of thousands of Americans are dying each year from mental health-related concerns, and psychedelic-assisted psychotherapies have shown promise in treating mental illnesses in the studies to date. In contrast to some perceptions, psychedelics do tend to have very low rates of addiction and overdose. That being said, all medicines do have risks. And by understanding how psychedelic compounds work at the molecular level, also how they interact with the non-drug elements of that psychotherapy, is important for optimizing effectiveness and maximizing therapeutic access. 

 There are many people to acknowledge here, including my collaborators, our funders, and the other members of the lab. Thank you very much for taking the time to listen to my talk. I hope you found it engaging and interesting. And remember that mental health is a key community effort. Taking the time to support those around you is always time well spent.