Skip to main content
[siteorigin_widget class=”WP_Widget_Media_Image”][/siteorigin_widget]

The promise and challenges of psychedelic therapy- an overview of the science for therapists, psychotherapists and psychologists

Article written by Inwardbound co-founder Rob Coffey. Rob Coffey (MIACP) is a psychotherapist and transpersonal therapist, and co-founder of Inwardbound Psilocybin Retreats in the Netherlands ( He is a professional member of MIND- the European Foundation for Psychedelic Science, and is currently working on a research collaboration with the Trinity College Dublin Psychiatry Department on the therapeutic benefits of psilocybin.


Research into the therapeutic use of psychedelics is currently undergoing a major renaissance, after a decades-long hiatus as a result of the political fallout from the previous psychedelic revolution in the 1960s. This article intends to give an overview of the current psychedelic science, and look at the promise and challenges of psychedelic therapy. It is important for psychotherapists to be aware of the current developments in psychedelic science for two reasons. Firstly, to be aware of the therapeutic potential of psychedelics as well as their dangers, and secondly, to consider how best to support clients who self-experiment with psychedelics to integrate and process their experiences.

Psychedelics are a term meaning “mind manifesting”, “denoting a group of chemical compounds that, when taken, dramatically alter consciousness for a period of between one and eight hours” (Forde 2019).

The ‘classic psychedelics’ (DMT, ayahuasca, LSD, mescaline, peyote and psilocybin (the active ingredient in ‘magic mushrooms’)) are seeing an explosion in scientific study of their therapeutic potential. MDMA (methylenedioxymethamphetamine) is not considered a classic psychedelic but is included in this article due to its therapeutic properties. This renaissance is being led by prestigious research institutes such as MAPS (the Multidisciplinary Association for Psychedelic Research), the John Hopkins Center for Psychedelic and Consciousness Research in the US, and the Beckley Foundation and the Centre for Psychedelic Research at Imperial College, London in the UK.

Psychedelics are currently illegal in Ireland under the Criminal Justice (Psychoactive Substances) Act 2010, however a clinical trial is currently taking place in Tallaght Hospital/ Trinity College Dublin on the use of psilocybin for treatment resistant depression.

The Therapeutic Promise of Psychedelics

“When delivered safely and professionally, psychedelic therapy holds a great deal of promise for treating some very serious mental health conditions.” — Dr Robin Carhart-Harris (Head of the Centre for Psychedelic Research, Imperial College, London) (Carhart-Harris 2019)

The ‘classic psychedelics’ all have a similar mechanism of action. They are serotonergic agonists which cause activity in serotonin receptors. Most notably, they temporarily reset the Default Mode Network (DMN) (Canal 2018). The Default Mode Network is responsible for our sense of ego- self, and our thoughts. Neuroimaging studies have consistently shown that psychedelics significantly reduce DMN activity, as does meditation, and that this correlates with the experiencing of ego-dissolution (or losing the sense of self). This “resetting” of the DMN could be linked to the antidepressant effects of psilocybin. (Carhart Harris et al 2012, 2018).

A recent study on the “Long-term effects of psychedelic drugs” states that some of the changes that can occur include: enduring changes in personality/attitudes, depression, spirituality, anxiety, wellbeing, substance misuse, meditative practices, and mindfulness (Aday et al 2020). Mystical experiences, connectedness, emotional breakthrough, and increased neural entropy were related to these long-term changes in psychological functioning. Finally, the study showed that with proper screening, preparation, supervision, and integration, limited aversive side effects were noted by study participants. (Jacob et al 2020)

Psilocybin for depression

Psilocybin is a naturally occurring psychedelic compound produced by more than 200 species of fungii. A landmark 2017 study conducted by the Beckley/Imperial Research Programme, published in the Lancet Psychiatry, provided the first clinical evidence for the efficacy of psilocybin-assisted psychotherapy to treat depression, even in cases where all other treatments have failed. The findings showed that “psilocybin was well-tolerated, and induced a rapid and lasting reduction in the severity of depressive symptoms” (Carhart-Harris et al 2017).

A more recent randomized clinical trial published in the Journal of the American Medical Association Psychiatry, found that “psilocybin administered in the context of supportive psychotherapy (approximately 11 hours) produced large, rapid, and sustained antidepressant effects” in patients with major depressive disorder. (Davis et al: 2020)

Extraordinarily, the effect sizes reported in this study were approximately 2.5 times greater than the effect sizes found in psychotherapy, and more than 4 times greater than the effect sizes found in psychopharmacological depression treatment studies (ie SSRIS).

The therapeutic benefits of psilocybin go beyond the treatment of depression. One of the pioneers of psilocybin research, Dr Roland Griffiths of John Hopkins, showed that psilocybin can induce mystical-type experiences which can have profound and transformative effect on people’s lives : “Fourteen months after participating [in one study], 94% of those who received psilocybin said the experiment was one of the top five most meaningful experiences of their lives; 39% said it was the single most meaningful experience “(Griffiths et al 2011).

According to Amanda Fielding of the Beckley Foundation :“We’ve noticed that the people who experience the most ego dissolution, which can be expressed as having a mystical experience, are very often the people who have the best results in treating their condition” (Meehan 2017)

MDMA for Post-Traumatic Stress Disorder and Relationship Counselling

MDMA is known for inducing heightened energy levels, euphoric mood, openness and empathy (Wardle 2014). Currently, six study sites in five European countries are involved in the “Open Label Multi-Site Study of Safety and Effects of MDMA-assisted Psychotherapy for Treatment of PTSD”. In the US, the Multidisciplinary Association for Psychedelic Studies (MAPS) is undertaking a plan to make MDMA-assisted therapy into a Food and Drug Administration (FDA)-approved prescription treatment by 2023. With preliminary research being extremely promising, the FDA has granted ‘Breakthrough Therapy’ Designation for MDMA-Assisted Therapy for PTSD.

Other studies have shown the potential of MDMA in enhancing relationship satisfaction, which shows potential application for use in couple’s counselling. (Monson et al: 2012): “[People on MDMA] don’t have the same level of fear response. They feel more relaxed, so they can tell each other things they might not otherwise be able to talk about,” says Katie Anderson, a lecturer at Middlesex University, who has studied MDMA use in couples therapy. (Anderson et al 2020)

Psychiatrist Bessel Van Der Kolk, author of the seminal book on trauma, ‘The Body Keeps the Score’ (Van der Kolk 2014), has described from his own experience how MDMA “offers the possibility for people to have a deep inner experience in which they can tolerate things that were intolerable before, and experience perspectives that were previously inaccessible. For deep inner healing to occur, we need to help people get into a state where they can observe what happened to them with a sense of calm and self-compassion, and then put it into the past, where it belongs”

But he also cautions about the importance of using these substances in the correct way : “At the same time, we must keep in mind that it’s unlikely that MDMA will prove to be the magic pill. It’s not the only way to get to that deep state of self-observation and self-awareness. It’s very important that people not go wild and create excessive expectations. But does the current work with psychedelics and MDMA have great promise? Absolutely. I’m still worried that people will be careless and take it without well-trained guides. You need to be accompanied by a very good therapist to use these drugs, once they’re legal, for optimal therapeutic advantage.” (Van der Kolk 2018)


Ayahuasca, a powerful DMT containing hallucinogenic mix used as a traditional medicine by the indigenous peoples of the upper Amazon, is seeing a huge growth interest for its therapeutic potential. Research is currently on going on the therapeutic use of ayahuasca for addiction, and for certain psychiatric disorders (Frecska et al: 2016, Geddes 2020)

In one recent study published in Nature, “Effects of ayahuasca on mental health and quality of life in naïve users” showed that after the use of ayahuasca, more than 80% of those subjects showed clinical improvements in psychiatric disorders that persisted at 6 months. The study showed significant reductions in depression and psychopathology, with long-term users showed lower depression scores, and higher scores for self-transcendence and quality of life, as compared to their peers” (Jiménez-Garrido et al 2020).

In the confines of this article it is not possible to cover all the psychedelic currently research ongoing. However, it worth mentioning that studies showing promise in the treatment of major depression, anxiety and cluster headaches with LSD are occurring at the University of Basil, Switzerland; in the treatment of alcoholism with LSD and psilocybin in the US and Switzerland; and the treatment of opioid addiction with Ibogaine in New Zealand and Mexico.(Tatala 2020) . Most recently, research has shown promising results in using psychedelics to treat Alzheimer’s and dementia suggesting a “… potential role for both sub-perceptual ‘micro’- and psychedelic-doses as a strategy for neuroprotection and cognitive enhancement in prodromal Alzheimer’s disease.” (Vann Jones 2020).

The challenges of psychedelics

Widespread media coverage of the new wave of psychedelic research has found its way into the media and popular culture, leading to a rise in self-administration of these powerful substances. The 2020 Global Drug Survey asked 110,000 people about their drug use. Some 6,500 people, almost six per cent, said they used recreational drugs to deal with mental health issues (Kilander 2021). “Self-reporting of these sessions was really positive with 86 per cent saying the drugs were very helpful. The concern is that these are a vulnerable population and they really need to have good oversight. But that’s not available yet. The treatment is more risky for this group that is using it to self-treat mental illness and emotional distress, but it’s also potentially more beneficial for them as well”. (Barrett 2021)

I present the current scientific literature on psychedelic research with a strong caveat, that if these substances are not administered in a carefully controlled set and setting, in the correct dosages, that they may be harmful and even dangerous. In extremely rare instances, psychedelics can evoke a lasting psychotic reaction, more often in people with a family history of psychosis (Barrett 2016). It should be noted that all the scientific research mentioned states the importance of proper screening, preparation, supervision, and integration.

That said, a large-scale 2015 meta-analysis by a team of researchers from Johns Hopkins and the University of Alabama showed ‘classic psychedelics’ to be surprisingly safe (Henricks et al 2015).

The study analyzed data from more than 191,382 people between 2008 and 2012 during the annual National Survey on Drug Use and Health. More than 13 percent of those surveyed (27,235 people) had used ‘classic psychedelics’ at some point in their life. The respondents who had used a classical psychedelic were 19 percent less likely to have been in psychological distress during the previous month, 14 percent less likely to have had suicidal thoughts over the last year, 29 percent less likely to have made plans for suicide and 36 percent less likely to have attempted suicide in the past year than the survey respondents who had never used psychedelics.

Data from the first era of psychedelic research supports this idea. Around 10,000 participants are thought to have participated in LSD research in the 1950s and 60s, and the rate of psychosis, suicide attempts and suicides during treatment “appears comparable to the rate of complications during conventional psychotherapy, according to an analysis of data from this era” (Passie 2008).

According to Dr Mike Scully, Chair of the Addictions Psychiatry Department, at the College of Psychiatrists of Ireland, addiction to psychedelic drugs is very rare. “When I was training as a junior doctor, hallucinogenic drugs had a really negative reputation. They were considered habit and dependence-forming substances and were said to be very damaging. But when you actually look at the modern literature on psycho-pharmacology, that impression does not appear to be evidence-based,” he says. “For example, I looked at a paper from 2015 published in the Journal of Psychopharmacology, from a large population study of 130,000 adults in the United States, including 19,000 psychedelic users. It failed to find evidence for a link between psychedelic use [of LSD, psilocybin or mescaline], and mental health problems” (Meehan 2017)

As the pioneer of psychedelic therapy, Dr Stan Grof, succinctly said: “Psychedelics are tools. There’s nothing intrinsically good or bad about them. It’s like asking whether a knife is dangerous or useful: it depends on who is using it and for what purpose” (Winter 2009)

On the therapeutic potential of ‘bad trips’

One of the main concerns relating to psychedelics is the fear of a ‘bad trip’. These concerns are valid, with the literature showing that about 10–30% of participants in a therapeutic setting have challenging or very challenging experiences. (Barrett et al 2016) . However, the evidence suggests that if meaning can be found for those challenging experiences, a ‘bad trip’ can still have therapeutic value.

According to MAPS (2020) the type of psychedelic crises that may arise: “ “Old traumas can be remembered and relived. These memories can be of a physical nature (reliving one’s birth, childhood abuse and/or illness, memories of famine and/or war, accidents, rape are some of the possibilities of re-emergence). These memories can also be of an intellectual, emotional nature (reliving verbal abuse, a lack of basic emotions, body contact, love, nurture, or a disassociation due to a traumatic experience).” Whether these experiences are re-traumatising or beneficial depends largely on the therapeutic container provided (Van der Kolk 2014).

In a very large study in the Journal of Psychopharmacology, 1,993 individuals completed an online survey about their single most psychologically difficult or challenging experience (ie their worst “bad trip”) after consuming psilocybin mushrooms in a non-therapeutic setting (Carbonaro 2016). Thirty-nine percent rated it among the top five most challenging experiences of their lifetime. The level of difficulty of experience was positively associated with dose, the higher the dose the more likely to have a challenging experience.

Despite these difficulties, 84% endorsed benefiting from the experience and the study concludes that “the incidence of risky behavior or enduring psychological distress is extremely low when psilocybin is given in laboratory studies to screened, prepared, and supported participants.” (Carbonaro 2016) . As Vickor Frankl pointed out, “Those who have a ‘why’ to live, can bear with almost any ‘how’”, it would seem that helping people find meaning in challenging experiences is the key to unlocking the therapeutic potential of ‘bad trips’. (Frankl 2006)

Some of the challenges facing the emerging field of psychedelic therapy

In a recent paper “Consciousness, Religion, and Gurus: Pitfalls of Psychedelic Medicine” , Dr Matthew Johnson of John Hopkins Centre for Psychedelic Research sees the main challenges as (1) Sloppiness regarding use of the term “consciousness”. (2) Inappropriate introduction of religious/spiritual beliefs of investigators or clinicians. (3) Clinical boundaries and other ethical challenges associated with psychedelic treatments.

According to Johnson: “My observation suggests that psychedelic therapy is like putting a magnifying glass on many of the aspects of non psychedelic psychotherapy, including both positive aspects, e.g., the importance of rapport, and negative ones, e.g., potential for abusing a position of expertise or authority.“ (Johnson 2020)

Other major issues facing the emerging field of psychedelic therapy include the lack of trained therapists, unrealistic expectations, the potential for the abuse of power, the potential for re-traumatisation during the psychedelic experience and the question of how to safely navigate sexual trauma in the psychedelic space (Coffey et al 2020).

The renaissance in psychedelic science poses major challenges for the psychotherapy profession in general. What role, if any, will psychotherapy play in the therapeutic use of psychedelics? Do psychotherapists have a role in protecting clients from the potential harmful effects of psychedelic self-experimentation, and what role, if any, will psychotherapists play in helping clients integrate psychedelic experiences?

The psychedelic renaissance raises major legal, ethical and educational considerations for the mental health field in general. It is only a matter of time before the considerations arising from this psychedelic renaissance become more prevalent, and for this reason it is important that the psychotherapy and psycholology professions be prepared.

Rob Coffey (MIACP) is a psychotherapist and transpersonal therapist, and co-founder of Inwardbound Psilocybin Retreats in the Netherlands (

He is a professional member of MIND- the European Foundation for Psychedelic Science, and is currently working on a research collaboration with the Trinity College Dublin Psychiatry Department on the therapeutic benefits of psilocybin.


Aday, J et al (2020) Long-term effects of psychedelic drugs: A systematic review, Neuroscience & Biobehavioral Reviews,Volume 113.

Anderson, K., R, P. and Boden, Z. (2018) An affective (re)balancing act? The liminal possibilities for heterosexual partners on MDMA. In: Affective Inequalities in Intimate Relationships. Routledge.

Barrett, F. S., Bradstreet, M. P., Leoutsakos, J. S., Johnson, M. W., & Griffiths, R. R. (2016). The Challenging Experience Questionnaire: Characterization of challenging experiences with psilocybin mushrooms. Journal of psychopharmacology (Oxford, England)30(12), 1279–1295.

Barrett (2021 5 March) Australians use risky DIY psychedelic drug treatments for mental health

Canal C. E. (2018). Serotonergic Psychedelics: Experimental Approaches for Assessing Mechanisms of Action. Handbook of experimental pharmacology252, 227–260.

Carbonaro, T. M., Bradstreet, M. P., Barrett, F. S., MacLean, K. A., Jesse, R., Johnson, M. W., & Griffiths, R. R. (2016). Survey study of challenging experiences after ingesting psilocybin mushrooms: Acute and enduring positive and negative consequences. Journal of psychopharmacology (Oxford, England)30(12), 1268–1278.

Carhart-Harris RL, Erritzoe D, Williams T, et al (2012) Neural correlates of the psychedelic state as determined by fMRI studies with psilocybin. Proc Natl Acad Sci U S A. 2012;109(6):2138–2143. doi:10.1073/pnas.1119598109

Carhart-Harris, R.L., Roseman, L., Bolstridge, M. et al. (2017). Psilocybin for treatment-resistant depression: fMRI-measured brain mechanisms. Sci Rep 7, 13187.

Carhart-Harris RL, Bolstridge M, Day CMJ, et al. (2018) Psilocybin with psychological support for treatment-resistant depression: six-month follow-up. Psychopharmacology (Berl). 235(2):399–408. doi:10.1007/s00213–017–4771-x

Carhart Harris (2019) Imperial launches world’s first Centre for Psychedelics Research

Coffey, R et al. (2020). A guideline for navigating sexual trauma and harm prevention in psychedelic ceremony spaces

Davis AK, Barrett FS, May DG, et al. (2020) Effects of Psilocybin-Assisted Therapy on Major Depressive Disorder: A Randomized Clinical Trial. JAMA Psychiatry. doi:10.1001/jamapsychiatry.2020.3285

Forde, D. (2019 5 September). A Beginners Guide to the Psychedelic Renaissance.

Frankl, V (2006). Man’s Search for Meaning. Beacon Press.

Frecska E, Bokor P, Winkelman M. (2015) The Therapeutic Potentials of Ayahuasca: Possible Effects against Various Diseases of Civilization. Front Pharmacol. 2016;7:35. doi:10.3389/fphar.2016.00035

Geddes, L. (2020 November 9). Psychedelic drug DMT to be trialled in UK to treat depression

Griffiths R, Richards W, Johnson M, McCann U, Jesse R. (2008) Mystical-type experiences occasioned by psilocybin mediate the attribution of personal meaning and spiritual significance 14 months later. J Psychopharmacol. 22(6):621–632. doi:10.1177/0269881108094300

Hendricks PS, Thorne CB, Clark CB, Coombs DW, Johnson MW. (2015) Classic psychedelic use is associated with reduced psychological distress and suicidality in the United States adult population. J Psychopharmacol. Mar;29(3):280–8. doi: 10.1177/0269881114565653. Epub 2015 Jan 13. PMID: 25586402.

Kilander, G. (2021 6 March). More people are using psychedelics to treat their own mental health, study shows.

MAPS 2020. Varieties of Psychedelic Crises.

Meehan, A. (2017 15 January). Psychedelic drugs: A higher purpose?

Monson CM, Fredman SJ, Macdonald A, Pukay-Martin ND, Resick PA, Schnurr PP (2012) Effect of Cognitive-Behavioral Couple Therapy for PTSD: A Randomized Controlled Trial. JAMA. 308(7):700–709. doi:10.1001/jama.2012.9307

Noller, G. et al (2017): Ibogaine treatment outcomes for opioid dependence from a twelve-month follow-up observational study, The American Journal of Drug and Alcohol Abuse, DOI

Passie, T. et al (2018) “The pharmacology of lysergic acid diethylamide: a review.” CNS Neuroscience & Therapeutics 14.4: 295–314.

Tatala, D. (2020 August 25). Every psychedelic study currently going on in Europe.

Van der Kolk, B A. ( 2014) The Body Keeps the Score: Brain, Mind, and Body in the Healing of Trauma. Viking.

Van der Kolk, B.A. el al. (2018) Learning to Bear the Unbearable: How MDMA Works. Psychedelics: The Future of Talk Therapy?

Van Jones, S.A et al (2020). Psychedelics as a Treatment for Alzheimer’s Disease Dementia. Front. Synaptic Neurosci., 21 August 2020

Wardle, M. C., Kirkpatrick, M. G., & de Wit, H. (2014). ‘Ecstasy’ as a social drug: MDMA preferentially affects responses to emotional stimuli with social content. Social cognitive and affective neuroscience, 9(8), 1076–1081.

Winter, A ( 2009 August). Stanislav Grof On Nonordinary States Of Consciousness.

Winstock AR, Timmerman C, Davies, E (2021), Global Drugs Survey (GDS) 2020 Psychedelics Key Findings Report