The administration of psilocybin to healthy hallucinogen experienced volunteers

The administration of psilocybin to healthy,hallucinogen-experienced volunteers in a mock-functional magnetic resonance imaging environment: a preliminary investigation of tolerability

This study sought to assess the tolerability of intravenously administered psilocybin in healthy, hallucinogen-experienced volunteers in a mock-magnetic resonance imaging environment as a preliminary stage to a controlled investigation using functional magnetic resonance imaging to explore the effects of psilocybin on cerebral blood flow and activity.

The present pilot study demonstrated that up to 2 mg of psilocybin delivered as a slow intravenous injection produces short-lived but typical drug effects that are psychologically and physiologically well tolerated. With appropriate care, this study supports the viability of functional magnetic resonance imaging work with psilocybin.

Psilocybin (4-phosphoryloxy-N,N-dimethyltryptamine) is a tryptamine hallucinogen and the pro-drug of psilocin (4-hydroxy-N,N-dimethyltryptamine), a partial agonist at the 5-HT2A receptor (Nichols, 2004) and the active constituent of psilocybe mushrooms.

In the late 1950s, psilocybin was identified and isolated from its natural source (Hofmann et al., 1958, 1959). Like the pharmacologically related hallucinogen, lysergic acid diethylamide (LSD), psilocybin was commonly used as an adjunct to psychoanalytic psychotherapy for the treatment of a wide range of psychiatric conditions (Grinspoon and Bakalar, 1979; Leuner, 1963).

In the mid-1960s, the popularization of hallucinogenic drugs stimulated an increase in recreational use. Subsequent adverse events attracted media attention and public and political concern, leading to the withdrawal of production (Spencer, 1966) and the introduction of significant restrictions on research (Lee and Shlain, 1985).

It has only been in the last 15 years or so that clinical researchers have begun to work again with this group of compounds (Griffiths et al., 2006; Vollenweider et al., 1997). Functional MRI (fMRI) has emerged as a powerful imaging modality, but psilocybin has never been administered in this environment. Recent guidelines for human research with hallucinogens cautioned against exposing ‘intoxicated’ subjects to potentially anxiogenic situations (Johnson et al., 2008).

In accordance with this advice, the present study sought to assess the tolerability of intravenously administered psilocybin in healthy, hallucinogen-experienced volunteers in a mock-fMRI setting as a preliminary stage to a controlled investigation using this imaging modality. Intravenous administration was chosen on the basis of previous work indicating good tolerability and a fast onset and brief dura- tion of subjective effects (Hasler et al., 1997), convenient for fMRI studies.


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7 thoughts on “The administration of psilocybin to healthy hallucinogen experienced volunteers”

  1. Hello!
    My name is Drew.
    I’ve watched interviews on “London Real” and would be very interested and willing to help you research.
    I’ve had several mushroom experiences, and thoroughly enjoyed them.
    Just recently I’ve teamed up with a friend where we take a tab of 170ug every 4 weeks.
    Since experimenting, my life has changed so much for the better.
    We do it in the comfort of home, and we effectively meditate for 1-8 hours on it.
    I feel so much calmer than usual. I feel I can handle things a lot better. I feel (excuse the term) more enlightened. Things that would bother me, or make anxious doesn’t effect me anymore. I focus on my work for a lot longer, without feeling drained. It’s actually given me a breath of fresh life.
    Me and friend have both said that we want this in our lives. To respect it, by not doing it every week, or not taking massive doses. Our ethos is basically that the world is a chaotic busy place, and no one seems to be able to dedicate a day out of their month to just sit back, relax and meditate for a whole night.
    I find it a remarkable, spiritual and privileged experience to undertake.
    When I’d watched the interviews I knew I’d be up for helping.
    So here I am, writing this small message to you.
    Thank you for reading, and feel free to contact if I can assist you and the experiments in anyway.

  2. Hello, I’m am 43 year old male living in oxford and suffered from depression and anxiety for 20 some years and I am a chronic suffer. I am very interested in participating on this type of drug trial. In my 20’s I have picked my own mushrooms once or twice and quiet enjoyed them and apprieate the benefits.

  3. Hi, I have read your articles and I am currently on anti depressants. I have tried different kinds as I have mild PTSD from military service and suffer from depression constantly. I would very much like to assist and be a volunteer for future trials.

  4. Hello everyone
    I’m on antidepressant from couple of years and I try many different types. Right now I have worst time ever. I try mushrooms which one found my self on last season 2016. I have found but that was very difficult for me. I go nearly everyday for few weeks for couples of hours a day. I pick onbly for one time but that was amazing experience. I feel like newborn I feel like treat at all. That was best time in my life. Only after one time i feel great for 2 or 3 months. But that is finish now and nothing help me know again. My life is hell and really need help. Please if someone can contact me.

  5. Hello,
    I am 63 years old and am struggling with severe depression. I used many psycedelics during my teens and well into my 20s. Actually used LSD as a method of marriage communication. It was very helpful. Now 35-40 years later and nothing helps this deep depression I’m in. I’ve become very isolated. I would be so interested in volunteering to use any form of psycedelics. Please let me know if you have any trials going on. Thanks Roxene

  6. I’m Karl a 40.yr Old Male who’s Depressed & got Anxiety who also would like 2 try Philosybin Treatment as I don’t believe in the treatment available @ the moment

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