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Dr. Jordi Riba has been studying the pharmacology of ayahuasca for nearly 2 decades. Gabor Maté met Dr. Jordi Riba at the MAPS conference, and then went to Spain to visit him at his lab. They spent a few days talking about the effects of ayahuasca and the brain imaging studies that Dr. Riba had been conducting at San Pau Hospital, in Barcelona.

GABOR: So, as far as I know, you are the only one who’s done brain scan studies. Is that right? You’re also the only one that has purified and standardized the doses of ayahuasca.

RIBA: That’s right. We’ve had this project of conducting studies in humans. So we started doing this formulation of standardized ayahuasca.

GABOR: You are the only one who has standardized the doses of ayahuasca?

RIBA: So far I am. I think we’re the only group that has served ayahuasca to humans in a research setting, and we’ve done this with standardized doses of ayahuasca.

GABOR: And what made you do that? What was the interest for you? What led you to that kind of research?

RIBA: It’s a kind of research. With ayahuasca, it’s basically because it was something mysterious. I had always been interested in psychotropic drugs. So when we first learned of the ayahuasca churches expanding their activities to Europe and we knew that there were some groups in the Barcelona area I decided that I wanted to do some research on this.

So we were invited by the people who were organizing the ayahuasca sessions to attend, and we were also able to interview the participants. What really struck me was that they appeared really calm; after they had taken ayahuasca they remained seated with their eyes closed and it seemed like nothing had happened, but later when i interviewed them, they told me that they had revelations and visions, or they had very interesting insights into their personality: the way they behave, how they related to others. And they found this was very useful to their everyday life and their personal growth.

GABOR: And their past, perhaps, as well?

RIBA: Yeah, they had also had emotional memories of their past; sometimes happy events, sometimes traumatic events. What I found amazing was that a simple chemical compound was able to elicit these spectacular effects in the human brain. So this is what motivated me to start doing some pharmacological research on ayahuasca & neuroscience research into the mechanism of action of ayahuasca.

Basically because no one has explained – so far – how these drugs work. And how we have these neuron imaging techniques & mirror imaging techniques that were not available 20 – 30 years ago.

GABOR: So you’re actually showing the parts of the brain where the plant is active then?

RIBA: Yes, we conducted this mirror imaging study- but not in long-term users – to see if there was any damage or anything. But what we did was, as I’m interested in ayahuasca, check for changes in brain activity following this acute administration.

And you have to implement some specific tasks to see activation, and this is part of the research we are currently conducting. We are assessing people, not under the affects of ayahuasca but regular users in their normal state. We are having them perform some tasks which lead to activation. Then we check to see if there is any hyper or hypo activation of these regions. This is the research that we are conducting right now.

GABOR: And the brain areas that you did see activity in – does that give you a sense at all of the function or activity of ayahuasca in the brain? Does it help to explain the experiences that people describe? Is there a correlation between what you saw on the scans and what you understand of what people experience with it?

RIBA: Well, I wanted to know how these substances work: how they interact with the human brain. So to study this, we have used several techniques. We measure subjective effects by means of questionnaires, to know exactly what people were experiencing in these states. We have measured plasma levels of the different alkaloids that are present in ayahuasca. We have measured also the brain electrical activity, how this is changed after the administration of ayahuasca, and more recently we have conducted the first neuroimaging study that has ever been done with ayahuasca.

GABOR: During the experience?

RIBA: During the experience, yes. We administered ayahuasca to a group of people who had experience with the drug and, at the time they were having their more intense effects around 90 minutes after administration, we took an image of the brain by means of a technique known as Single Photo Emission Computed Tomography (SPECT). [From this,] we got the information on which brain areas were lighting up during the acute effects of ayahuasca.

GABOR: And you were correlating that with blood levels with some of the products in ayahuasca?

RIBA: Yes, we found a good correlation between the levels of DMT and the intensity of the subjective effects people are experiencing. There’s also a correlation between DMT levels and many other physiological variables, but mainly with – or most importantly with – subjective effects: changes in brain electrical activity. And we also saw these activations by means of S.P.E.C.T.

GABOR: So, specifically, you were looking at which brain areas are triggered or involved. And what did you find out?

RIBA: So, we found a hyper activation of certain areas of the brain. What was most interesting, despite people having very intense visual phenomena, we didn’t see any activation of the primary visual areas of the brain. What we saw was an activation of what is known to be the most evolved areas of the brain: the pre-frontal cortex, the neo-cortical areas in the pre-frontal cortex, and also areas that are directly related to the processing of emotional information.

GABOR: So, the limbic areas?

RIBA: Limbic areas, that’s right. The areas that are know as the anterior cingulate, also the insula – which has been related to insight into the self, and also areas that are mediating memory processes.

We saw activation of the hippocampus and a very little area that is known as the amygdala- which is very involved in the processing of emotional information. And what we know from other neuroimaging studies is that all these areas light up together and collaborate in situations in which people are primed to recover emotional memories.

So, what we found in these neuroimaging studies is that what people tell us about the re-experiencing of these emotional memories – actually – relates or can be justified by the brain areas that we found to light up.

GABOR: So, what do you make of the fact that the visual cortex doesn’t get activated, but pre-frontal areas or associated areas do?

RIBA: So this means that the ayahuasca induced experience is not mediated by brain areas that are in charge of processing primary sensory information but others that are, hierarchically, higher up. So, my view is that under the effects of ayahuasca, people start recovering previously stored emotional information that is already in their brain. So this experience is not so dependent on external factors but more on experiences people have already had.

GABOR: But nevertheless, they’re memories that are not generally or not necessarily accessible to the individual, ordinarily, in the usual course of life.

RIBA: Right. So, I think with ayahuasca, the individual has access to certain memories that are there – the person knows them – but what it does is it allows the individual to re-experience these memories in a very intense and emotional way. So some time ago I used to joke saying that ayahuasca allowed people to have random access to memory, or that the ayahuasca experience was a “random access to memory”, but I think that it’s not random: because what usually comes up are memories that have a very important emotional load. It’s not like remembering yesterday what you had for dinner, but perhaps how you felt about a relative or a loved one some years ago. You remember some experiences that are emotionally relevant to you.

GABOR: Now, I’d like to ask you about a certain aspect of this. People sometimes have images and sometimes images, or the visions, are just random colors and patterns and shapes: geometric or energetic and so on, but sometimes they are creatures, people and beings of all kinds. And sometimes they’re very benign and sometimes they’re scary – but that it always has an emotional contact. Now, how do you put together the emotional content, which I think is memory, and the visions, where do they come from?

RIBA: Well, from our studies I think i can say with some certainty that they are not generated in the primary visual areas. That is generated more in the pre-frontal cortex somehow, in the ‘mind’s eye’.

GABOR: So, they’re more an act of imagination?

RIBA: I would think so, yes. I would be more in favour of this explanation. But people with experience with ayahuasca usually tend to not pay much attention to this display of geometrical patterns and they tend to focus on the visions that have an emotional load, usually.

GABOR: Yeah. No, my view is, is that the emotional memory comes first and then the mind creates an image to accompany, its always like a dream-state, where the mind will make up a story to – to a point – for a certain emotion.

RIBA: Perhaps the emotion is accessed and then the image is created by the pre-frontal cortex.

Either way, we didn’t see any activation in areas in charge of processing sensory information – like visual art does. We didn’t see any activation at all. So this is something that didn’t add up – but is very interesting.

And what we did see were these activations in the frontal sections of the brain: in the near cortex but also in more primitive areas of the brain which are in charge of processing emotional information and also memory information. And the way I interpreted this data was that ayahuasca somehow retrieves information that is already in their brains.

RIBA: So the pattern of activation I found is similar to the pattern of activation that is seen in studies measuring the retrieval of emotional memories. And, if you analyze the subjective reports of the volunteers – the people taking ayahuasca – most of the time these visions they are having, they are not emotionally neutral. There is always some emotional load in what they are seeing, or hearing, or experiencing.

GABOR: Well, there is a phrase called ‘implicit memory’ which is not as much recall, as it is the ingrained template and memory of emotional experiences – or emotionally powerful experiences- that the (person) might not even recall.

RIBA: Well from the reports of participants, it’s always what we call episodic memory, something that happened to them and they can put into words. And there is always something that is emotionally relevant to the participant: like some conflict they have had with someone who is emotionally close to them: their partners, spouses or parents, children. It has this load, positive or negative effect.

GABOR: Now, you also mentioned that the anterior cingulate lights up?

RIBA: Yes, that’s right – this activation we see in the frontal cortex, in the medial aspects of the frontal cortex. It encompasses the near cortex but also the anterior cingulate.

These have been shown to participate in the integration of cognitive and emotional information.

GABOR: Just for my information, how would it be different if you took an MRI on someone that is just having a dream? How would it be different?

RIBA: There are some studies conducted with P.E.T and S.P.E.C.T, but I’m not familiar with that. What I can tell you is that we have done EET studies, measuring changes in brain electrical activity for a long time. It’s quite different. You can’t really say that the pattern of electrical activity you see there, [is similar to what] you would observe in sleep. In sleep you have different stages. This is different: these stages can be very different in terms of the electrical waves that you are seeing there.

GABOR: And what you were saying is that you see more activation on fast beta?

RIBA: Yes

GABOR: Under ayahuasca?

RIBA: Yes. What we see is a shift from the slower frequency delta – to the faster frequency beta. You can get the maximum increase in beta- when subjects have their most intense subjective affects and you have the highest blood levels – this is associated with excited activity in the brain cortex.

GABOR: And to some extent you did show a dose/response effect which [proves] the higher the dose – the greater the impact. The reason that interested me is because the shamans, when they gave out the medicine, sometimes would give lesser or greater quantities. And sometimes in the ceremonies you give someone less and they have a greater effect. So in practice that doesn’t seem to be a dose/response effect, not in practice- not in terms of peoples subjective experience.

RIBA: Yes, we were told this many times before we started our research and we were really intrigued. This would have indicated that this does not follow the typical patterns of pharmacology of drug effects. But to answer this question you really have to standardize conditions; you have to standardize doses, and you have to standardize the way you monitor effects. Because sometimes people can say they have had a more intense effect because the information or the experience they had was more relevant perhaps to them, or more emotional. But, if you administer these questionnaires, which can measure different aspects of the experiences, perhaps you may see that you had a more intense effect in the emotional realm with a lower dose, but with a higher dose you had more intense effects in the perceptual realm.

Of course we are always reporting this response as the average of many participants so, to that extent, I’d be quiet confident that there is a dose/response effect.

GABOR: That may not be reflected in subjective experience, is that what you’re saying?

RIBA: Yes. You’re always measuring the same aspects with a standardized questionnaire. But that doesn’t mean that the quality of what they experience would be more relevant with a lower dose than a higher dose.

GABOR: Now what about the fact of the people who work with the ayahuasca? They would say it’s not just about the pharmacology- it’s also about the chanting, the environment.

RIBA: I totally agree with this. I’ve interviewed many people who have participated in ritualized sessions and music has a tremendous impact on the experience.

GABOR: Is that something you could ever show on a brain scan, like could you do [with] some people while listening to music. Is that something you could do?

RIBA: Yes, I would be really interested to see how music influences the experience. Do different regions light up, or if you get a more intense effect on the regions that we have already shown to be active? Definitely, I’d like to do that, involving music and ayahuasca.

GABOR: I can tell you one subject’s experience. I was learning at Takiwasi in Peru and Jacques Mabit. At some point I had this desire to purge but nothing was happening and he starts chanting this song, very rapidly, and within a second I had purged. And he told me later the song was designed to make people purge.

RIBA: I would think that you can have ayahuasca show what those responses are: monitored in regards with its interaction with the body and the brain. This is the starting point. You activate, perhaps, these neurons and they start firing at a higher rate. Blood flow starts increasing in these regions. But after that – you can modulate the experience by all the external stimulations.

GABOR: Now, I understand that there doesn’t seem to be a visual apparatus activated but people are much more sensitive to light and to sound during the ceremony. So how do I understand that?

RIBA: In my interpretation what you are seeing – your visions – are generated at a very high level in the hierarchy of the brain. It’s not a basic, visual lower level.

GABOR: I understand about light sensitivity I’m just talking about sudden flashes of light is much more intense.

RIBA: We didn’t design specific experiments to measure that. In our neuron imaging studies all participants kept their eyes closed when these measurements were conducted. So we had to control that. They had eye shades, and what we thought would happen would be that these visual areas would get activated. They didn’t. But I’m not saying that they are more sensitive somehow to external stimulates: that we have not yet measured yet.

GABOR: If I asked you to summarize what is it that you’ve learned: I mean I understand your data, your findings. If you had to encapsulate, and say what we have learned about ayahuasca and brain functions, how would you sum that up?

RIBA: What we’ve learned from [the] different techniques we’ve used is, first, the brain’s electrical signature of ayahuasca – which is quite different than other drugs which interact with other neuronal systems. We did this study comparing ayahuasca with other phenomena – it had not been studied in other psychedelics. Studies on LSD are very old, and they did not analyze the data in the way we do today. Also, what I think is really relevant is this information we’ve obtained regarding the brain regions that are involved in the genesis of the ayahuasca. I think this is an important step – no one before had done this.

GABOR: I don’t know if you permit yourself to do this, but if you can take off the scientific cloak for a minute. If I could just ask you personally: based on what you understand about this plant and how it’s used: it’s reported effects on people and on what you learned here. What, if any, correlation can you make between the reported and historical information of ayahuasca and what you’ve seen in these brain studies?

RIBA: If I have to, for a moment, forget about all these scientific terminology, I would say that – and this is my personal opinion – ayahuasca brings you closer to your heart.

And that would be very similar to what shamans, the traditional users of ayahuasca, have always told us.

GABOR: Is there anything that you saw during your brain studies that would give you any kind of scientific handle on that? Any kind of template for understanding what you just said?

RIBA: Oh, well you see that all these brain regions that were activated are all related to emotional processing. In scientific terms, being closer to the heart would be like getting these brain areas processing much more information: acting at a higher level, or being more active.

GABOR: On a pharmacological level. Are we talking here about the DMT or the alkaloids or both of them? What, if anything, is invoking that heart response?

RIBA: There’s been a lot of speculation about this because some researchers think that ayahuasca is not the DMT: that ayahuasca is the combination of the effects of DMT plus the betacarbolines. But from the data from my studies, I see that the time you have harmine in your system is very brief. So I don’t think that – in most of my participants – it really had any effect on the nervous system.

GABOR: Is it possible that harmine is potentiating something?

RIBA: There are these two other substances that you have there of course; there are metabolites: you have harmine, harmaline, THH, harmol and also harmalol. These are not such powerful monoamine oxide inhibitors. But the β-carbolines are a potent inhibitor, so it’s possible that all these components are generating a final effect which is different than that caused by pure DMT.

GABOR: So, the tea has these several components and you’ve been looking at that.

Can you talk about that?

RIBA: It’s very complex from the chemical point of view. As you know, ayahuasca is obtained by brewing together two different plants; banisteriopsis caapi and psychotria viridis. And we know that the psychoactive compound which is know as dymethyltriptamine or DMT – and this DMT interacts with certain serotonin receptors in the brain. These receptors are mainly located in the cortex, they are known as serotonin 2A receptors, and basic research has found that the activation of these receptors leads to a release of an activatory transmitter known as glutamate. But, DMT is very labile. So, when orally ingested, it gets very easily degraded by enzymes that are present in the liver and the gut – so if a brew only containing DMT were ingested, DMT would never reach systemic circulation.

GABOR: It wouldn’t get to the brain.

RIBA: It would never get to the brain. Banisteriopsis caapi, on the other hand, has a series of several compounds, known generically as betacarbolines, and these compounds can inhibit the metabolic breakdown of DMT.

GABOR: So it protects the DMT?

RIBA: It protects the DMT, that’s right. And it allows the DMT to reach systemic circulation: into the central nervous system and the brain.

GABOR: So it’s like a vehicle?

RIBA: Well it’s what we call a pharmacological interaction: when one drug prevents the breakdown of the other.

GABOR: Okay. So when they get to the brain then, do these beta-carbolines have any activity on their own are they just there to protect the DMT?

RIBA: So, DMT has this mechanism of action: it interacts with 2A receptors in the brain, but betacarbolines also have a pharmacological effect, they inhibit an enzyme known as monoamine oxidase so when these betacarbolines inhibit the action of this enzyme – the levels of our endogenous neurotransmitters are increased; so you get increases in noradrenaline, in endogenous serotonin and also in dopamine, so, the overall effect is very complex. You have a direct antagonism of DMT, but also the increased levels of all these other [endogenous neurotransmitters].

GABOR: There was a class of anti-depressants which are not much used any more but were called the monoamine oxidase-based inhibitors – so the betacarbolines are similar, are they?

RIBA: Yes, they act by the same mechanism; somehow they would be like a natural anti-depressants. But these compounds are also metabolized when they are ingested and they are not present in the body for many hours.

GABOR: Now, when it comes to the actual effect of ayahuasca, the drink, do we know which components do what? Or to what extent they are responsible for the different effects of the tea?

RIBA: This has not been studied systematically. So, what we see when we study ayahuasca is the global effect of all the components present in the tea. There have been some studies of pure DMT, administered intravenously or subcutaneously, to overcome this problem of oral metabolism. But, there haven’t been any systematic studies of the interaction of betacarbolines and the DMT in humans.

Now, which alkaloids are responsible for the effects? That would mainly be dimethyltriptamine. Of course, these effects of dimethyltriptamine are modulated by all the other substances that are present there: tetrahydroharmine might be increasing serotonin levels, and serotonin levels have always been associated with emotions or the emotional state. And some of the minor alkaloids might be generating also a monoamine oxidase inhibiting effect – that could also be potentiating adrenaline and dopamine.

So, ayahuasca is quite complex from the biochemical point of view.

But we see that the peak of DMT in the blood, and when the highest levels are obtained, corresponds with the time-point where the most intense subjective effects or physiological effects are observed. So, the data available indicates that DMT would be the main element responsible for the effects we observed after the administration of ayahuasca. For example, the levels of tetrahydroharmine, [another compound found in ayahuasca], peaks in 4 or 5 hours after oral administration and in most cases people do not experience any subjective effects at this time point, they have usually disappeared after this interval.

GABOR: Really? In the laboratory?

RIBA: Yes, in the lab. With some exceptions, as I told you.

Some people have effects earlier on, some people later on, but statistically after 4 hours in- you don’t get any subjective effects any more.

GABOR: Because certainly in ceremony, I could tell you that people very often have effects for much longer than that. I have experienced that personally as well. I don’t know how to correlate that. I’m just thinking that the laboratory setting is somewhat different from the ceremonial setting.

RIBA: Yes, of course, what we don’t see at four or five hours is the intense visual effects.

GABOR: No, that’s true.

RIBA: You find that people report other kinds of sensations: like sedation or sensation of a feeling of tranquility.

GABOR: Tranquility, clarity, presence, yeah.

RIBA: That, that could be an after-effect of the main DMT related effects, or a rebound effect.

GABOR: Right, right.

RIBA: But certainly, at four hours, very little DMT is present in the system. You have still other alkaloids. Maybe these late effects could be related with these other alkaloids, which haven’t been eliminated yet.

GABOR: So if you look at the brain four or five hours later, according to the S.P.E.C.T. studies, are you still seeing anything?

RIBA: We haven’t done any studies at this time. The only study we’ve done was at the peak of the visionary effects.

GABOR: I see.

RIBA: The problem is always that in the lab you have most of the variables under control, and in the field you don’t. And many people, I don’t know, start telling you things that don’t quite match what you see in the lab. So it’s difficult to compare the situation- because on many occasions, people have had more than one dose. Situations are very difficult to compare, there could be many factors that could be playing a role here.

GABOR: But, but do you see the possibility that the experience isn’t just based on that – the DMT levels are just one aspect of the experience? They may be an important aspect, but not the only thing that can influence people’s experience? Or do you think the others just artifacts?

RIBA: I don’t have an immediate explanation to that. Because sometimes people have very strong effects when you have the big concentrations of DMT, and then after several hours these levels are normally lower- but they may still have visionary effects because the levels are probably still high enough to illicit this kind of experience. And, perhaps when the effects are less intense – perhaps once people have thrown up and have emptied their stomachs of this irritating substance – these effects are even more pleasurable than what they had two hours before. Perhaps, I think that what they learn in this late phase of the experience is more valuable to them. Or, I don’t know, more interesting than what they have had in the initial two hours after taking ayahuasca. So, it’s difficult to draw a conclusion without controlling very well all the variables that are involved.

GABOR: Well, I guess what the question raises is whether you can actually study this thing fully?

RIBA: I don’t know. It’s not a question that’s easy to answer.

GABOR: I guess what I’m asking is whether you can reduce the whole experience to pharmacology?

RIBA: I guess pharmacology is a trigger, but then the subjective experience each person has is very private and personal and it changes from one person to the other: and its based on their previous emotional experiences, their autobiography, etc. It gets influenced by so many factors. So, I guess, the drug is just the trigger of the experience.

I think the experience can be modulated by many factors; music would be a factor, the shaman would be another factor and in the end – the sum of all these modulating factors would be the experience that the person has.

RIBA: But I find it very hard to answer to all these questions about the naturalistic contexts in which ayahuasca is taken, because my work’s been restricted mainly to the lab. There were a lot of comments as to whether ayahuasca would show those dependent effects, because you hear constantly people saying that once they took a very small dose of ayahuasca and they had a very intense experience and then they took a large amount and the experience was uninteresting or there was no experience at all.

But if you control all the factors, you administer accurate dosages and you control expectancy by designing the studies including blind design; double-blind, single-blind design, then you can see that there’s a clear dose/response effect and that means that the larger the amount of ayahuasca you give, the more intense the experience will be and, if you can, you are able to measure this with questionnaire.

That can yield a numeric value of the intensity of the experience.

GABOR: And you showed the value of that by questionnaire, that scale?

RIBA: Yes.

RIBA: So it’s always very difficult to compare what you see in the lab with all these other settings because there are so many factors in these other settings that are not being accurately controlled, right? But I’m not saying that the experiences people have in these other contexts have no value – not at all – but that if you want to study what the drugs do to different physiological, neuropsychological, neurophysiological variables or neuroimaging variables- then you have to very accurately control the dosages that you’re giving, the expectancy, etc.

GABOR: Now do you also study the effect of the DMT?

RIBA: No, I studied ayahuasca.

GABOR: It corresponds to DMT levels.

RIBA: It is ayahuasca. And we measure the levels of all the alkaloids, all the substances that are included in the material. And what we see is that you get the best correlation with the DMT levels, not with the tetrahydroharmine, harmine or harmaline levels. In fact, harmine gets very, very easily degraded when it’s ingested, so it doesn’t even reach systemic circulation and it will hardly reach the CNS (central nervous system), or at least that’s what we’ve seen in most of our volunteers.

GABOR: So, it will be what, degraded in the liver?

RIBA: Yes, in the liver and gut, it is what is called a first pass metabolism effect, first-pass effect.

GABOR: If we set out today with our scientific techniques and technologies to develop a product that would combine DMT with something that would allow to be absorbed. How long would it take us?

RIBA: What do you mean by that? If we didn’t know anything about it?

GABOR: If we didn’t know anything about it. If you just said, we wanted to create an experience for people that would put them closer to their heart. How long would it take us to do it?

RIBA: Ages I guess.

GABOR: I’m just trying to figure out how those guys (yageceros/ayahuasqueros in the Amazon) did it, you know?

RIBA: Trial and Error. Testing for new food sources… maybe.

NEUROIMAGING STUDIES ON THE ACTIVITY OF AYAHUASCA

RIBA: So, we studied the statistical comparison between the ayahuasca condition and the placebo condition. We found activations in the frontal medial-cortex and the anterior-cingulate cortex and these areas are in charge of the interaction of cognitive and emotional information.

We also saw activations in the anterior part of the insular – bilaterally – and this area is known to receive visceral inputs.

So these areas receive input from all the organs, all the viscera in the organism, and it plays a role on somatic awareness.

Ayahuasca activated some other interesting areas, like we found with the amygdala, and the hippocampus. As we said- these areas are also involved in the processing of emotional information and of memory.

GABOR: Now the amygdala is specifically important in relationships, attachment, and so I imagine that people are remembering their relationships or their attachment relationship with their parents.

RIBA: During the ayahuasca sessions?

GABOR: Yes. That would go along with what I’ve seen.

And some people seem to become more aware of their internal processes: both in terms of physical processes in the body, and then in terms of emotional, psychological states. So, what about your studies would help to explain that?

RIBA: Specifically, in terms increased awareness of bodily processes, we saw activation of the insular: which is known to mediate somatic awareness, for instance, in cases of visceral pain. So, the insular might be mediating these effects people report.

GABOR: So, it’s not so much that it causes pain, but it makes them more aware of the pain they have inside themselves already.

RIBA: People having visceral pain, because – let’s say they have cancer, shows that they have an increased activation of the insular. So, in our study, during the acute effects of ayahuasca, we see this brain area is more activated: it receives more blood flow. So, perhaps, the subjective report of increased bodily awareness could be mediated in the brain by this increased activation of the insular.

GABOR: And which brain areas would be associated with emotional insight or the sense of awareness that people have on the psychological level?

RIBA: Well the limbic areas are also activated; like the anterior-cingulate, also the amygdala – which could be mediating those emotional effects of ayahuasca. The anterior-cingulate, which is in the medial part of the frontal cortex, is known to inter-connect information coming from the emotional brain with information coming from higher areas processing cognitive information.

GABOR: So, is that where awareness would be mediated? Is that where awareness of an emotion would be mediated? Like, there’s the emotion that they’ve experienced in the amygdala – but where’s the awareness of that?

RIBA: Some researchers have also associated the insular with emotional awareness. All the studies by neurologist Dr. Antonio Damasio say that the area where “feeling states” occur is the insular – that’s his hypothesis.

CONCLUSIONS

GABOR: What is your projection about the use of these substances in the Western world in a more open and professionally accepted fashion? I mean your work is very preliminary work I know, but nevertheless you’ve made a step that no one else has made before. I’m just wondering what you see in the long term process here that might lead to more of an openness: more curiosity to take these questions that you’ve begun to answer a little further?

RIBA: I think that the effects these substances bring about-  and the approach that the people interested in them have – are quite different from the view of mainstream society.

So I don’t think it is going to be an easy path to convince society at large that these substances have potential.

And there will always be this question – who has the right to administer these substances? We are always criticizing the system, or the medical establishment or the pharmacological establishment like preventing people from coming close to these substances. But when we advocate the use of these substances it’s also the medical establishment that says we’d like to use them. So should it be restricted to medical doctors, should people have free access to these substances? And they are not devoid of risks, so should someone be in charge of guiding their access to such substances? I don’t have an answer for that.

So what we’re now doing is accessing long-term users of ayahuasca – and we want to test whether the repeated intake of ayahuasca can induce changes in the brain. We are measuring brain structure, and we are going to assess whether there’s an impact in grey matter. We are going to measure cortical thickness, and also the connections between brain regions. We want to see if there are changes at this level and we are also doing functional tests to see if long-term users of ayahuasca are processing information in different ways from people who are ayahuasca naive – who have never used the tea.

GABOR: Now, certainly studies have shown that in people who abuse drugs like heroin or alcohol or cocaine, there are long-term changes in white matter and grey matter and connections too. So far, are you seeing any changes at all with ayahuasca or has it been long enough so that you can tell?

RIBA: Well, people say they can feel changes in the way they relate to other people, in the way they think. So the question we ask ourselves if this changes – will it be measurable- by means of this technique? So we’re doing this by means of MRI scans.

GABOR: Over what period of time will you do this? How long will you be following people?

RIBA: We are recruiting people who have used ayahuasca for at least three or four years on a regular basis. They need to have taken ayahuasca at least 50 times. And we will only test them once. So, we might do a follow-up in 2, 3 years time but right now we are only doing one, one batch of tests.

GABOR: Are you comparing them to controls?

RIBA: Yes, we are comparing them to matched controls: people who are of the same age, same gender, who have the same level of education but who have never taken ayahuasca or any similar drug.

GABOR: Is it too early to say if you’re getting any sense of any findings at all?

RIBA: It’s too early right now, because we haven’t finished testing people, so we don’t have any results yet.

GABOR: My final question at this moment would be, what risk do you see with this particular substance?

RIBA: I know people who have suffered psychologically from the use of ayahuasca – people close to me.

GABOR: I’ve seen people. I saw one person that had a psychological breakdown after a ceremony. But he probably should have been excluded because he has a history of psychosis, and probably wasn’t a good candidate. The people you see – I wonder if they have a negative experience because maybe they didn’t get the appropriate kind of help.

RIBA: I feel people should have the choice to choose whether they want to try a substance and use it.

But I think we’re always trying to justify why this is bad for someone. I’ve been working on this for 15 years and I’ve seen many people taking this and most people having a positive experience, but also some of them having negative experiences. And, also, how people react to these negative experiences – usually people try to reassure themselves saying there was something wrong before that person got involved with ayahuasca.

But this close friend I know had things happen with ayahuasca, and never had any problems before with psychoactive drugs. But one day, he had psychotic crisis. I don’t know- he couldn’t solve that for himself, so he needed medication. He was devastated because he couldn’t understand why that had happened to him: he had always had such a good relationship with ayahuasca. So he went back to taking ayahuasca, and he had a second crisis and in some way remained sensitized to these drugs. After that he had another crisis with MDMA and also with another psychedelic. So after these three or four crises, he’s decided that this is not for him. He won’t be able to take these anymore. But that was his life before this crises appeared. And he had no history of psychiatric illnesses himself, or his parents.

That was also quite devastating for his relationship, for his family.

GABOR: I want to say two comments on that. Number one is that I can’t know this, but imagine- like other people might say- that this man had something deep in him that he hadn’t uncovered before and he just went a step beyond where he could handle. Number two, that in proper health, he could have integrated and dealt with those experiences. So perhaps he didn’t have the support that he could have had. Of course that’s the way with any kind of medication: a lot of people can do okay and do repeatedly okay – but then they take the same medication and (suddenly) have very negative reaction. So we’d expect that with any kind of substance.

RIBA: Yes, but I think he was in a good environment to get some kind of support when this crisis appeared. Because that was during a session, in church. And from what he told me, he really did get that good support from very experienced people who had taken ayahuasca many times, and are followers of the many traditions we have today. And also, what was very hurtful to him, is that he felt very rejected. Because this is something that many people having trouble with psychedelics feel: that the community of users will say that there was something wrong with them. They will never admit that there was something wrong with the psychedelics.

That is also very common, and we should reflect on this.

GABOR: Some kind of dogma.

RIBA: Yes, he felt like they were trying to sweep him under the carpet. “Don’t talk about this, don’t tell anyone about this, keep it to yourself and we’re sorry – but there was something wrong with your brain prior to that”. So no one will accept that these drugs, or any other substances might caused the crisis. So I think we should be careful about this. They probably have a potential for doing good, but they also have a potential for doing harm. The problem is you can never know- this person had no history that could be used to know that he had problems, but in the end he had them.

GABOR: Yes, and I agree we have to be very clear about the potential dangers. You know, unfortunately, sounds like with the state of mind that he was in – [the church community] couldn’t handle the bad news they were given.

They wanted to protect themselves – rather than help him.