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Psychedelic Therapy with Cannabis

In current scientific research, cannabis is being explored not only for remedies for various bodily illnesses, but also as a medicine for adverse mental conditions. After recreational cannabis became legal in some states in the USA in 2012, a few independent groups began openly exploring the potential of cannabis for treating mental conditions, such as PTSD. Some treatments use a high-dose, ‘psychedelic’ cannabis experience to induce mystical experiences for healing. In this blog, we’ll explore this movement.

Psychedelic Prohibition

The world’s first prohibition of cannabis was in the late 14th century in Egypt (Rosenthal 1971:129), followed by Madagascar in 1787 (Campbell 2012:437), and Rio de Janeiro in 1830 (Bewley-Taylor et al. 2014:6). By 1925, under a UN convention, the use of cannabis became illegal worldwide. Only in December 2021 was cannabis officially rescheduled by the UN as a potential medicine.

In a process that began in 1966, apart from a few religious exemptions—such as for the use of peyote by Native Americans in North America—most psychedelic substances were banned globally for not only recreational but also psychotherapeutic use. By 1977, no further scientific studies of psychedelic substances were permitted under international rules. However, small-scale use of LSD for terminally ill patients persisted in a few medical centres in Switzerland and the USA.

Psychedelic Therapy

Clinical research conducted on the effects of psychedelics began in the 1950s, notably in Saskatchewan, Canada (see Dyck 2008), established that LSD and mescaline could be highly effective in treating alcoholism, depression, trauma and other mental problems. However, prohibition terminated research.

The tide began turning around twenty years ago when clinical research on psychedelic substances gradually resumed, and permits for research began to be reissued. There are now active psychedelic research programmes at Imperial College in London, Berkeley UC, Johns Hopkins University in Baltimore, Maryland, the Dell Medical School at the University of Texas, the Icahn School of Medicine at Mount Sinai, and the Psychae Institute in Melbourne.

In 2006, Roland Griffiths and his team at Johns Hopkins University began publishing their research on how controlled psilocybin sessions could induce a ‘classic’ mystical experience Griffiths et al., 2006; 2011, 2019). Research conducted by MAPS (Multi-Disciplinary Association for Psychedelic Studies), headed by Rick Doblin, has shown that MDMA can work effectively against PTSD (MAPS 2022). Other studies conducted in London and Cardiff have tested LSD, psilocybin, DMT, 5-MeO-DMT, and ketamine for treatments for depression and PTSD, with excellent results.

Overall, the way psychedelic treatments seem to work is that what may be called ‘mystical experience’ seems to reset the brain, a bit like turning off and on a computer to fix a glitch or by defragging the brain’s hard drive. The vision of oneself from another, ‘greater’ perspective seems to have the profound capacity to heal negative mental conditions.

Therapeutic Cannabis

Over the last twenty years or so, abundant evidence has re-emerged from medical studies of the usefulness of cannabis for a host of medical conditions (Verma et al., 2021). It is now well known that cannabis can provide effective relief for migraine, fibromyalgia and pain generally and for the adverse symptoms of epilepsy, multiple sclerosis, and anti-cancer drugs. CBD has been shown to retard breast cancer cells, and the cannabis medications manufactured as Dronabinol and Nabilone are effective against anorexia, Alzheimer’s and Parkinson’s diseases (Verma et al. 2021:44).

Popular publications on medical cannabis, such as by Backes (2017), detail dozens of medical conditions and the strain of cannabis appropriate for each condition. Sarris et al. (2020:2) note a survey that among people who use medical cannabis, 64% use it for pain relief, 50% for anxiety, and 34% for depression.

A recent trend in medical research has been the exploration of cannabis, particularly the CBD component, for adverse mental conditions. It is well known that the CBD in cannabis has a more soothing effect, while the THC is more stimulant. It has been shown that CBD can help reduce anxiety, depression, insomnia and cognitive impairment. Studies have indicated that between 28% and 75% of patients with PTSD benefit significantly from cannabis (Sarris et al. 2020:6; Abizaid et al. 2019). Some doctors in the USA are now prescribing CBD cannabis for some patients with PTSD (Lutz 2021; Travers 2019), with promising results.

Schizophrenia and ADHD

Some people have particular genes (BDNF, CNR1, COMT, AKT1, and DRD2) that make them more prone to schizophrenia (Sarris et al. 2020:7). It is generally advised that people with latent schizophrenia or a history of psychosis do not use cannabis, as it may induce unwanted symptoms. However, CBD has been shown to be beneficial for treatment-resistant schizophrenia and may confer protective effects on young people at high clinical risk from psychosis. Preliminary evidence also indicates that cannabis could be effective for ADHD (LaFrance et al. 2020; Sarris et al. 2020:8).

An irony in the current phase of research is that despite regulatory changes, scientists everywhere, even in countries where recreational cannabis is entirely legal, are still severely hampered in their ability to obtain licences for cannabis research: “Legal weed is everywhere – unless you’re a scientist” (see Owermohle 2018).

Psychedelic Cannabis

Besides the research being conducted by scientists on cannabis for mental therapy, several groups have developed their own therapy programmes using cannabis. One group, the Centre For Meaningful Mindfulness, in Denver, Colorado, run by Daniel McQueen, uses high-dose, ‘psychedelic’ cannabis to treat mental conditions such as trauma and PTSD and for conflict resolution (see McQueen 2021).

The centre runs regular sessions, which generally follow protocols developed in other psychedelic treatment programmes. Longer sessions are called Conscious Cannabis Circle, while shorter sessions are called Cannabis Healing Meditation. Patients are first assessed for suitability to find out if they are using other drugs, if they have contemplated suicide, experienced epilepsy, or have other conditions that would render them unsuitable for psychedelic cannabis treatment.

The centre considers high-dose cannabis to have a psychedelic potential equal to other ‘classic’ psychedelics, such as LSD. One difference, though, is the voyager’s ability to retain with cannabis a sense of agency, unlike when on LSD, for example. It is claimed that this controlled sense of agency can work even better than other psychedelics when clearing trauma, as the voyager is thought to be able to use this sense of agency to change attitudes to the past and to current behaviour. At the end of psychedelic sessions, there is a meditation and integration session.

Psychedelic Sessions

Voyagers prepare by writing down their intentions and then journaling their experiences. Meditations on the chakras, body scans, and prayers are made to the seven directions. Groups of participants lie in a circle, and a sequenced music program is played. Sitters are in attendance. During the ritualised sessions, participants are encouraged to explore where stress or trauma is stored in the body and examine and unblock it.

The sessions can also include deep breathwork, which intensifies the experience. If experiences become too intense for participants, they are given CBD, by spray or vape, to moderate the effects of the weed.

Cannabinol (CBN)

A precise mix of different kinds of cannabis is employed for sessions. Sativas are believed to enhance creative introspection, indicas a greater body awareness, and hybrids work as heart-openers (McQueen 2021:42). Between six and nine—and up to sixteen—kinds of cannabis are used in a blend, which participants smoke. In fresh cannabis buds, there is very little cannabinol (CBN), a compound first isolated in 1896 (ElSohly and Gul 2016:12).

But aged by sunlight, THCA (‘A’ = acid) breaks down into CBNA. CBN, which is not psychoactive on its own, is formed by the decarbyloxation of CBNA. The addition of high-CBN weed to a sativa/indica mix is said (McQueen 2021:57) to enrich visions and allow the voyager to go deeper, perhaps by allowing more THC to be absorbed.

The Emergence of Cannabis Treatment Centres

McQueen’s cannabis treatment centre, the Centre for Medicinal Mindfulness, founded in 2014, is not the only organisation providing such programmes. Another cannabis therapy organisation in the USA is the Psychedelic Somatic Institute (PSI) (Psychedelic Somatic Institute 2022), where cannabis is combined with psychotherapy. Most sessions are conducted in Denver, where the Centre for Medicinal Mindfulness also conducts sessions.

In the UK, at over a dozen institutions around the country, Sapphire Medical is also providing cannabis to patients with PTSD if other anti-depressant medications (such as paroxetine or mirtazepine) or anti-anxiety medications (such as the benzodiazepine known as diazepam) do not provide adequate relief (Sapphire Clinics 2022).

It seems that there will be further developments, and new organisations will emerge which will use cannabis to treat not only physical but also mental problems.


  • Abizaid, Alfonso, Zul Merali, and Hymie Anisman (2019). ‘Cannabis: A potential efficacious intervention for PTSD or simply snake oil?’. Journal of Psychiatry and Neuroscience, vol. 44(2), pp. 75–78.
  • Backes, Michael (2017) [2014]. Cannabis Pharmacy: The Practical Guide to Medical Marijuana. New York/London: Black Dog and Leventhal Publishers/Elephant Book Company Limited.
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  • McQueen, Daniel (2021) [2019]. Psychedelic Cannabis: Therapeutic Methods and Unique Blends to Treat Trauma and Transform Consciousness. Rochester, Vermont: Park Street Press.
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  • Travers, Mark (2019). ‘Is Cannabis an Effective Treatment for PTSD?’. Psychology Today, 16th December.
  • Verma, Risabh, Farazul Hoda, Mawrah Arshad, Asif Iqubal, Ali Nasir Siddiqui, Mohammad Ahmad Khan, Syed Ehtaishamul Haque, Mohd Akhtar, Abul Kalam Najmi (2021). ‘Cannabis, a Miracle Drug with Polyvalent Therapeutic Utility: Preclinical and Clinical-Based Evidence’. Medical Cannabis and Cannabinoids, vol. 4, no. 1, June, pp. 43–60.
Cultivation information, and media is given for those of our clients who live in countries where cannabis cultivation is decriminalised or legal, or to those that operate within a licensed model. We encourage all readers to be aware of their local laws and to ensure they do not break them.

Matthew Clark

Since 2004, Dr. Matthew Clark has been a Research Associate at the School of Oriental and African Studies (University of London), where he taught courses on Hinduism between 1999 and 2004. He has spent many years in India, which he first visited in 1977, visiting nearly all important (several hundred) pilgrimage sites and trekking around 2,000 miles in the Himalayas. He first engaged with yoga in the mid-1970s and began regularly practicing Ashtanga Yoga in 1990. Since 2006 has been lecturing worldwide on yoga, philosophy, and psychedelics. He is one of the editors of the Journal of Yoga Studies and is one of the administrators of the SOAS Centre of Yoga Studies. His publications include The Daśanāmī-Saṃnyāsīs: The Integration of Ascetic Lineages into an Order (2006), which is a study of a sect of sādhus; an exploration of the use of psychedelic plant concoctions in ancient Asia and Greece, The Tawny One: Soma, Haoma, and Ayahuasca (2017); and a short book on yoga, The Origins and Practices of Yoga: A Weeny Introduction (revised edition) (2018).