Ayahuasca and Schizophrenia

One of the primary motivations for research into hallucinogens has been the hope that it might shed light on the cause and nature of schizophrenia. Such research is largely premised on the belief that hallucinogens generally are psychotomimetic -- that is, capable of producing a model psychosis, which allows researchers to study the mechanisms of psychosis in non-psychotic subjects. This assumption is worth challenging.

Schizophrenia is a complex disease that affects almost every area of thinking, feeling, and relating. One standard text lists the main symptoms of schizophrenia as auditory hallucinations, experiences of being controlled, delusions, disorders of thinking, and emotional and volitional changes. Similarly, a classic list of the first-rank symptoms of schizophrenia includes audible thoughts; voices heard arguing; voices heard commenting on one’s actions; the experience of influences playing on the body; thought withdrawal and other interferences with thoughts; diffusion of thought; delusional perception; and feelings, impulses, and volitional acts that are experienced by the patient as the work or influence of others. The DSM-IV diagnostic criteria for schizophrenia require at least two of the following: delusions, hallucinations, disorganized speech, grossly disorganized or catatonic behavior, and negative symptoms -- that is, affective flattening, alogia, or avolition.

The cognitive problems reported by schizophrenic patients include distractibility, difficulty focusing, an inability to screen out irrelevant information, feeling overloaded with too many stimuli at the same time, and problems with information processing, abstract categorization, planning and regulating goal-directed behavior, cognitive flexibility, attention, memory, and visual processing. The cardinal affective symptoms include affective unresponsiveness; emotional withdrawal; inappropriate affect; shallowness, coarsening, and blunting of affect; retardation of affect; perplexity; and anhedonia.

Now some hallucinogens can apparently mimic some of the features of schizophrenia -- primarily alterations in cognitive functions and depersonalization, including difficulty in focusing on objects, tension, changes in mood, distorted time sense, difficulty in expressing thoughts, dreamlike feelings, and visual hallucinations. Psilocybin ingestion, for example, has reportedly led to disturbances of emotion, sensory perception, thought processes, reality appraisal, and ego function. These effects included derealization, an altered sense of time and space, loss of ego boundaries, visual disturbances, difficulty in directing attention, and synesthesias.

Few of these features of schizophrenia, apart from visual and auditory hallucinations, time dilation, and synesthesias, appear to be part of the DMT or ayahuasca experience. And in schizophrenic illness, visual hallucinations occur with significantly less frequency than do auditory hallucinations, and schizophrenics suffer from thought disorders and loss of affect and insight -- none of which is true of DMT or ayahuasca.

No one can seriously claim to have produced a hallucinogenic model for schizophrenic illness as a clinical entity. Attempts to draw the analogy have proceeded by narrowing the comparison: thus, for example, researchers say that hallucinogenic experience should be compared with early and recently diagnosed rather than with fully developed schizophrenia, or with paranoid instead of undifferentiated schizophrenia, or with acute rather than with chronic schizophrenia. Such shifting ground does not inspire confidence.

And any such comparison must take both set and setting into account. As molecular pharmacologist David E. Nichols puts it, “No clinician experienced with these substances would fail to consider set and setting as primary determinants of the experience.” It is difficult to maintain that participants in, say, a Native American Church peyote ceremony are temporarily psychotic in any meaningful sense at all.

Indeed, a formal psychiatric study has shown significant differences between long-term members of the União de Vegetal (UDV), a Brazilian ayahuasca-using church, who consumed ayahuasca at least two times a month in religious rituals, and demographically matched controls who had never consumed ayahuasca -- but hardly in the direction of dysfunction. Personality testing instruments showed UDV members to be more reflective, rigid, loyal, stoic, slow-tempered, frugal, orderly, and persistent, and with higher scores on measures of social desirability and emotional maturity than controls. The ayahuasca-using participants also differed from controls as being more confident, relaxed, optimistic, carefree, uninhibited, outgoing, and energetic, and with higher scores on traits of hyperthymia, cheerfulness, stubbornness, and overconfidence. Significantly, on neuropsychological testing the UDV group demonstrated significantly higher scores on measures of concentration and short-term memory, despite the fact that many ayahuasca users reported significant psychiatric and substance abuse histories prior to their church membership.

Now, there are certainly some problems with this study. UDV worship is a structured and stable environment. Participants remain seated, with long periods of silence during which they seek self-knowledge through mental concentration, aided by ayahuasca. The ayahuasca-using study participants had to have been members of UDV for at least ten years, with at least twice-monthly -- that is, highly regular -- attendance at these services. Thus, the ayahuasca users may have been preselected for personality traits of stability, persistence, and orderliness. Moreover, while subjects and controls were matched for age, ethnicity, marital status, and level of education, there was apparently no attempt made to control for regular churchgoing, a measure on which the ayahuasca users were preselected for perfect scores, and which may well be correlated with personality traits for which they also scored high. Still, the study certainly gives no grounds to believe that long-term UDV church membership, along with concomitant twice-monthly drinking of ayahuasca, has caused any personality or cognitive detriment to its members.

One may be left to wonder what is going on here. Some authors may be engaged in covert stigmatization of the hallucinogenic experience. Others may be staking out turf -- that is, advocating their own clinical use of hallucinogens for specific therapies while disparaging their use “recreationally in unsupervised settings.” There may be other sociological reasons as well. There seem to be three different types of people involved in hallucinogen research -- those who synthesize, characterize, and consume hallucinogenic substances; those who are passionate about rat brains, state-of-the-art agonists, and beta-ray radiography of thin slides of tissue after the administration of labeled ligands; and those who are engaged in the actual care and study of persons with schizophrenia. Apparently these three groups do not talk to each other, or at least not much.


  1. "One may be left to wonder what is going on here."

    Isn't it simply that historically, up to the mid-60s, the only mainstream people who got a hold of 'hallucinogens' and got to study them were psychiatrists -- and therefore saw them through their psychiatrists' 'glasses' as 'psychotomimetic'? They had to describe the effects in terms they knew.

  2. what about experiencing schizophrenic symtoms for a couple days after ingesting ayahuasca

  3. I guess a lot would depend on what you considered a schizophrenic symptom. But DMT is apparently metabolized very rapidly, and I have not heard about anything like a schizophrenic symptom occurring several days after ingesting ayahuasca. If you have a reference you can give me, I would be very interested to hear about it.

  4. It is an interesting article. I have read somewhere (excuse - cannot find the source) some things that dr. Valentin Hampejs has said about schizophrenia, and the way that ayahuasca shamanism can be used to cure it in almost everyone. He seems to think it is more a spiritual affliction, with physcal (neurological) symptoms as a result of the spiritual affliction, hence the hallucinations. He states that the hallucinations are in fact real, and that the afflicted person does not have the normal "barriers" that "normal" persons do, to filter the non-essential input out.

  5. Hello Steve ~

    On reading your request of such an episode: here is an excerpt from my third ayahuasca ceremony several months ago...


    I looked over, behind the yurt and saw the black birds landing in a pine tree; I then looked around and felt a coldness approaching, a sudden vacuum filled the space around me and I felt very uneasy: I may have commented about it at this time, though do not recall, yet, I absolutely knew that ~ Here I was, some nine hours after my first and only drink of ayahuasca that night (where I did not vomit) and the journey had stepped into the ‘Real World’, that Death had stayed with me or that ‘that’ dimension was still open to me and I it, that something had crossed over and was with me…
    I heard a door close (possibly the yurt-door to my right) which delivered my heart back into a certain state-recollection of having journeyed to the deeper rooms and temples of Hell… I got up, stood and paused with a desire or need to go into the house, for some sort of focus or ease; still sitting at the campfire I felt a deathly presence come over me, a sickening heart wrenching utter dread of everything living in the now:

    I went into the house and noticed that the house was cosmically empty, it seemed so desolate, so still and dead, alone, abandoned, left to wither and die, cleanly diseased and utterly poisonous in its abandonment… I felt a chill and went to lay down by the sunny window on a large, thick cushion-mattress…

    {I now sense that somehow something within me was turned inside out: though I am not altogether sure why I feel this… It is a metaphor that lacks much power with me tonight.}

    I curled up a bit and lay there feeling very odd, as if something belonging to a kind of Death-reconciliation was about to come to a closure from all the deaths having not taken place in Hell in a finale-way, but, rather, was HERE in the PHYSICAL world to finish me, to give the story an ending:

    I began to make that smacking of my tongue on the top of my mouth gesture and lay, waiting, feeling like Time had suddenly blew away from the Earth and that something insanely hellish was about to land hard and unrelenting upon me. I truly sensed that I was in between two large, cold hewn stones, perfectly rectangle and ‘square’, just awaiting for them to flatten me beyond even the spirit of Flat itself: too, it felt as if the scream or screamer within was on board, laying on top of me, in me and that I was soon to be mortally attacked by the most violent and blood splashing event possible upon a soul’s presence in a human body.

    Then suddenly it occurred: I felt it, a sense of some sort of presence, a screaming, psychotic bleeding to death specter of some sort, yet it was everywhere, it was as though I was inside a huge jelly fish of absolute suicidal rage and desperation, that I was the ‘jelly’:

    I began to have deep and disturbing visions of running razor blades down my wrists and jabbing knives into my veins: a sense of overwhelming cosmic-death agony and anxiety fell upon me like a second layer of skin, heavy, sweaty and dead, rotten, putrid but alive and having a heart attack, a heart-rape-attack: it was as though not only my life was about to end, but, rather all Life with me… It was something so desperately deep that my identity shrank to about three or five percent of what I might now call ‘my voice’ or ‘being able to have my say’ and the only thing my soul could get out was a warning, a call for those around me to call the ambulance and keep me from killing myself…

    I got up and looked around: I quickly went outside and looked at the couple sitting by the campfire; I was cold, restricted, balled up inside, nothing, zero and empty and ruthlessly draining of Life or visa versa.

    A few other people were up and about: I asked the couple if they had seen the shaman or his helper, they said, ‘No, why?’ I looked at them and said that they need to call the ambulance right away because I believe I wished to kill myself…

    I stood there, cold, gone, though concerned and very, very simply lost, having no connection with life other than the desire to ask for help and protection from this inner destructive force about to annihilate me.

    Soon, a few more people gathered and I knew I needed to speak to the shaman, who was asleep in a private room located at the back of the house: one of the people there (the older man I identified the previous evening as ‘Father’) lead me there and to the door, he was taking too long in knocking softly, so I opened the door and went straight in and woke the shaman up, saying that they needed to call the ambulance because I wished to kill myself:
    I felt that enormous, ancient screams were welling up inside of me and that there was a deep and very enormous emergency on its way, the biggest emergency in the world. Whatever I was ‘then’, in that ‘Earth-moment’, I was too small to handle the energy, it was literally threatening my mortal life-container’s ability to live ‘normally’... It was an enormous and cosmic force, far outweighing all of ‘me’... Strange, to have been in this position ~ I am glad to have had a large support group nearby: this was a somewhat ‘totally’ unexpected thing to happen so long after the actual ayahuasca experience... Though I may be wrong/naïve about this; perhaps this is ‘normal’ for some (?)

    Round and round, something inside of me moved, seeming like it was a body made completely of metal, steel knives all over its whole body, bouncing off greased metal walls while trying to get out and to get at me. (My June 1, 2008 dream may relate to this ‘scene’ or description?)

    The 'shaman' took this in a very difficult way and said that I was acting very silly last night, that I was a ‘Know it all’, that I was even given by himself a slightly smaller amount of ayahuasca and yet, I wished to kill myself: he stated that I would get my monies worth, that I had paid him for something and that he was going to give it to me, that he would drive me to the train station so that I could jump in front of a train and kill myself: he said this several times and began getting dressed and walked out of the room, with me slowly following behind him…
    I went outside and was met with many people (the word had spread) and there were two key people who started to talk to me and then to the shaman, who I believe agreed to allow me to stay long enough to try and be dealt with by these friends, particularly his helper/assistant.

    The emergency flowing through me seemed as if it was never going to end and also the shaman’s impression of my previous night’s actions added to the suspicion that there was something very fatalistically wrong with me: a deep and utterly spellbinding state of split personality had fallen over me, where I was experiencing 3% of myself and 97% of something else, that I could not even ‘put’ my mind to: it was as though the desires of this other 97% simply separated from me and took my mind with it.
    This ‘something else’ was there, though not literally by a name or personality, it was as if it were someone else’s emotions, yet, too I was not ruling out that these were somehow surfacing because I had unlocked something inside myself by confessing this secret concerning my cat’s death, my first love’s abortion (and sexual details surrounding my relationship to my ‘first love’s’ last time with me/us together as a couple) to complete strangers in very explicit and humiliating details concerning my self punishments and true feelings.

    I also felt that something was still with me, that something had crossed over and was still around: my ayahuasca journey was still taking place in broad, three dimensional space, whereas it seemed that most others were ok and somewhat back, a little jarred, yet for the most part ‘safe’ and completely to themselves:

    I had actually gone in the opposite direction upon awakening; albeit most people’s conscious state after such a night of drinking ayahuasca is a bit dismembered from ‘ordinary life perceptions’.

    I was taken to the campfire and asked many questions as to what happened, why I wished to end my life, etc. I told the shaman’s friend that I was still halfway in that other world, that something had crossed over and the door was still wide open within me between these worlds: too, that I had always had this ‘door’ since childhood, that I did not know how to handle it, how to be with it…

    I also recall during my time sitting at the campfire that when people would come up and sit down next to me, that I could, once in awhile see flashes, like a slide picture (a transparent film) superimposed over them, of a person without skin… This was very disturbing; too, I had a very strong and sudden connection to one woman, that there was something within her that was connected to some very deadly issue concerning my relationship to my mother, something dreadful and haunting… My level of hypersensitivity was through the roof and the dead were rising and falling in and out of the living around me.

    My friends took me into the kitchen and sat me down at the table and gave me juice, water, fruit, coffee and some cheese and bread. I listened to people tell their stories in Dutch and tried to gather myself together while still feeling this door between the worlds was wide open: I was also feeling very distant and somewhat bashful: I recall saying to a friend that ~

    “Now I have to start all over again.” and he responded that what had occurred to me in the last three weeks took him ten years, yet, too, I understood deeply that this was not a rightful comparison, that it was an emotional investment towards me on his part and this was greatly appreciated, though in a new way of perceiving ‘appreciation’; it could be that I felt like a baby or young child, though not a good one.
    Another friend knelt down next to me and reminded me that he was the one who I lay my head in his lap while telling him that Trust had found me.

    He commented that I had found my power word (Trust) and went on to state that it seemed to him that I had never been truly happy in my life, that I needed to find ways to be completely happy by myself, etc. He was very encouraging, while the shaman’s helper was extraordinary in his acceptance and very careful emotions expressed around the situation.

    I simply sat there looking around: so much of me was simply dead and I felt the presence of Death, the presence of that ultra quiet Space and myself behind it, in it, my Space, the Space…

  6. A very interesting article. I stumbled upon it because I was actually looking for what others have thought about ayahuasca in comparison to schizophrenia because, having done it last night, it occurred to me that there may be very strong similarities. And I do not mean simply visual/auditory hallucinations and synasthesia, but rather depersonalization, confusion, difficulty processing reality and achieving the correct affect for social interactions -- strongly about four hours, and then lingering (mentally, without the hallucinations) for another several hours. I still feel deeply unsettled by some of the thought processes I experienced. The anonymous commenter above me gave a great account of how an ayahuasca experience might be similar to a sampling of schizophrenia, on a higher scale than what I experienced, but for what it's worth, here's another account...

    The first hour and a half was primarily euphoric and sensation-driven... I began to have a renewal of faith in the abstract deism of my adolescence -- but after denouncing this as absurd, I began coming up with alternative theories -- pyschological, anthropological, philosophical answers -- they all seemed to carry everyday, secular descriptions of reality through to their logical end, but this end seemed sick and horrifying and dehumanizing. Absurd metaphors occurred to me and impressed themselves on me and seemed to be not only metaphors but literal truths. Things like the world being some kind of graph-lined jelly and myself being a fold in a pattern, or else a lump of fleshy goo, and about humans being a sea of voices all speaking at once that I could hear in my head -- I began to believe that nobody was a separate mind, but rather, a different part of the same mind that I was a part of... some sort of nightmare that existed without anything beyond it. Like we were a computer system -- a giant recursion; systems taking in sensations, recording them, giving some output and having it somehow react with another output; compulsive fractals..

    I was lying beside my boyfriend for the second half of the experience, and at one point, felt an overwhelming joy and newnewss and couldn't stop laughing -- I felt I was witnessing everything both in the first and third person, existing on what seemed to be a "meta" level -- but it all seemed beautiful and fascinating and fun. Until I started noting my noting, "meta"ing the "meta" and became annoyed and distracted by how compulsive my thinking was. I tried to become "grounded" and see things as "real" again. I began mentally recoiling from every thought that occurred to me and wanting nothing but to fall asleep and "reset" and cease thinking, or at least become distracted by (enveloped by) some story or music. Existing in reality (and thus thinking) seemed hellish and inescapable.

    I thus couldn't interact with him properly at all -- tried to voice my thoughts but could only get out incoherent bits of it, felt frightened and ashamed, and shocked by his separateness and alienness. It was then that I began worrying about being crazy, and saw myself as a someone messing up, someone empty trying to suck something out of someone else -- stability or whatever else.

    When he and a friend sat nearby talking, I couldn't follow their conversation at all and couldn't shake the feeling that all of their perceptions of other people and of everyday realities were baseless and that they only believed them because people reinforce thoughts in each other in order to function. That's what religion used to do, but now we have new stories/games.

    The escape from this cycle of thoughts came by realizing that analyzing these games from a distant, depersonalized viewpoint is itself a game and that it can be fun, but need not be anything more -- neither profound nor insane. (Although, this conclusion is either a paradox or is begging the question -- if people aren't just playing a game of make-belief, than the game of believing that people are playing make-believe isn't a game... It's just wrong.)

    Needless to say, I still feel very strange and withdrawn. On the other hand, sleep did help when it (eventually, after a night of terrible insomnia) came.