Overview of Psychedelic-Assisted Therapy

The psychedelic-assisted therapy model involves the therapeutic use of a potent psychoactive medicine in conjunction with a psychotherapeutic process or other therapies to enhance treatment outcomes.

Although variations of psychedelic-assisted therapy exist, this approach typically includes:

Please ensure that you read through all items before proceeding by selecting each part of the image.

Preparation Sessions

Preparation includes the assessment of the client’s eligibility and suitability and the psychoeducation that underlies both informed consent and the building of skill in navigating alternate states of consciousness. This includes both psychological and physical dimensions of the experience, as well as its possible transpersonal and spiritual aspects for clients oriented towards those domains. Research (Carhart-Harris et al 2018) shows that how a client is prepared for psychedelic-assisted therapy influences the outcomes.

Psychedelic Medicine Sessions

Immersive Medicine Sessions are several hours in length, with variability depending on the substance used, goals for the session, client response to the psychedelic medicine selected, and the general unfolding of the session.

Integration Sessions

Integration begins following an immersive medicine session, usually within 24-28 hours of its completion. The etymology of the word ‘integrate’ refers to the act of bringing together the parts of a whole. This process can be viewed as bottom-up processing which will be discussed next module where sensory, somatic, emotional, and other dimensions of present moment experience form the primary, although not exclusive, building blocks of a cognitive formulation. There will also be clients who have a preference to process cognitively and emotionally. Psychedelic-Harm Reduction and Integration may thus be seen as a means of bringing together potentially disparate or discrete experiences, and ways of thinking about them, (common for example in post-traumatic stress), processing them in part, through the body, and ultimately bringing them into a coherent, functional, or helpful narrative.

All three of these components are thought to be critical to the therapeutic outcome. Research (Carhart-Harris et al 2018) shows that how a client is prepared for psychedelic-assisted therapy influences the outcomes. Research (Gorman et al., 2021; Mithoefer, 2016; Pilecki et al., 2021) also shows that Integration Sessions can provide opportunities for clients to make meaning of their experience during Medicine Sessions and use these experiences to make behavioural and life changes.

Learn More

In future courses, you will receive specific training for each psychedelic-assisted therapy protocol to help build upon this brief overview.

Psychedelic Medicines

In the following section, we will learn about the three psychedelic medicines that Numinus uses to deliver psychedelic-assisted therapy.

Please ensure that you read through all items before proceeding by selecting each title.

Psilocybin is a natural compound produced by numerous mushroom species most of which are in the genus Psilocybe. In the context of modern clinical research, it is manufactured synthetically to control potency and purity.

Psilocybin reliably induces profound changes in:

  • Sensory perception

  • Emotion

  • Thought

  • Sense of self, characterized by marked alterations in all mental functions, including:

    • Perception

    • Mood

    • Volition

    • Cognition

  • Self-experience (Griffiths et al., 2011; Studerus et al., 2012; Usona Institute, 2021)

Cultural Safety and Humility

At Numinus, we recognize and reaffirm Indigenous Peoples in their continued use and stewardship of sacred plant medicines in healing traditions and cultural practices since Time Immemorial. With humility and gratitude, we recognize Psilocybe mushrooms are sacred plant medicines rooted in Indigenous histories of the Mazatec, Nahua, and among other Indigenous Peoples, and modern psilocybin-assisted therapy would not be possible without their Knowledge, wisdom, and worldview.

Research conducted over the past 15 years has demonstrated the beneficial effect of psilocybin-assisted therapy on:

  • End-of-life anxiety and psychological distress (Agin-Liebes et al., 2020; Grob et al., 2011; Reiche et al., 2018)

  • Depression (Carhart-Harris et al., 2018; Robin L Carhart-Harris et al., 2016)

  • Substance use disorders (Bogenschutz et al., 2015; Johnson et al., 2014; Johnson et al., 2017)

  • Obsessive-compulsive disorder (Moreno et al., 2006)

  • Migraines (Schindler et al., 2021)

  • Demoralization (Anderson et al., 2020)

Learn More

To learn more about psilocybin, please watch Psilocybin Mushrooms and the Path to Higher Consciousness.

MDMA is a synthetic compound that was first developed by Merck in 1912. It was re-discovered by Shulgin in the 1970s and was introduced as an adjunct to psychotherapy at that time.

The effects of MDMA can include:

  • Increased feelings of interpersonal closeness

  • Increased compassion for self and others

  • Reduced anxiety

  • Reduced defences and fear of emotional injury

  • Making unpleasant memories less disturbing while enhancing communication and capacity for introspection (Bedi et al., 2014; Carhart-Harris et al., 2014; MAPS, 2021; Wardle & de Wit, 2014; Wardle et al., 2014)

Taken together, these factors provide the opportunity for reconsolidation of trauma-based memories and corrective emotional experiences within the context of therapy. MAPS PBC has been completing numerous studies in the United States, Canada, Europe, and Israel demonstrating the safety and efficacy of MDMA-Assisted Therapy to treat PTSD (Feduccia et al., 2018; Feduccia et al., 2019; Jerome et al., 2020; Mitchell et al., 2021; Mithoefer et al., 2019).

Research findings demonstrate that MDMA-assisted therapy may be efficacious for treating:

  • Social anxiety among adults with autism (Danforth et al., 2018)

  • End-of-life anxiety/psychological distress (Wolfson et al., 2020)

  • Alcohol use disorder (Sessa et al., 2019)

  • Eating disorders (Brewerton et al., 2021)

Learn More

To learn more about MDMA, please watch Your Brain on MDMA.

Ketamine is a synthetic compound that was first developed by Parke Davis as an analogue of phencyclidine in 1962. It was initially developed as an anaesthetic but has also been investigated for use in pain management and mental health treatment.

The effects of ketamine can include:

  • A time-out from ordinary, usual mind

  • A relief from negativity

  • An openness to the expansiveness of the mind with greater access to the self in a larger sense (Dore et al., 2019)

  • Acute changes in somatic, perceptual, cognitive, and affective processes (Kohtala, 2021; Mathai et al., 2020)

Research findings demonstrate that ketamine-assisted therapy may be efficacious for treating:

  • Depression (aan het Rot et al., 2010; Caddy et al., 2015; Caddy et al., 2014; Covvey et al., 2012; Coyle & Laws, 2015; Fond et al., 2014; Garay et al., 2017; Han et al., 2016; Hasselmann, 2014; Katalinic et al., 2013; Kishimoto et al., 2016; Kleeblatt et al., 2017; Kolar, 2018; Kraus et al., 2017; Lee et al., 2015; McGirr & Berlim, 2014; Papadimitropoulou et al., 2017; Papakostas, 2020; Romeo et al., 2015; Serafini et al., 2014; Zheng et al., 2020)

  • Post-traumatic stress disorder (Li & Vlisides, 2016; Walsh et al., 2022; Yavi et al., 2022)

  • Suicidal thought (Bartoli et al., 2017; D'Anci & Uhl, 2020; Dadiomov & Lee, 2019; Reinstatler & Youssef, 2015; Wilkinson et al., 2018; Witt et al., 2020)

  • Bipolar disorder (Alberich et al., 2017; Fornaro et al., 2020; McCloud et al., 2015)

  • Anxiety (Dore et al., 2019; Glue et al., 2018; Shadli et al., 2018), PTSD (Albott et al., 2018; Feder et al., 2014; Ross et al., 2019)

  • Obsessive-compulsive disorder (Rodriguez et al., 2013)

  • Substance use disorders (Azhari et al., 2021; Dakwar, Anerella, et al., 2014; Dakwar et al., 2017; Dakwar, Levin, et al., 2014; Dakwar et al., 2020; Dakwar et al., 2019; Dakwar et al., 2018; Jovaisa et al., 2006; Krupitsky et al., 2002; Krupitsky et al., 2007; Krupitsky et al., 1992; Krupitsky & Grinenko, 1997; Pizon et al., 2018; Rothberg et al., 2021; Shah et al., 2018)

  • COVID-19-Related Burnout and PTSD (Robison et al., 2023)

Learn More

To learn more about ketamine, please watch What Ketamine Actually Does to your Brain.

Learn More

To learn more about these and other psychedelic medicines within the context of psychedelic-assisted therapy, consider watching Michael Pollan’s How to Change Your Mind documentary series on Netflix.

References

aan het Rot, M., Collins, K. A., Murrough, J. W., Perez, A. M., Reich, D. L., Charney, D. S., & Mathew, S. J. (2010). Safety and efficacy of repeated-dose intravenous ketamine for treatment-resistant depression. Biol Psychiatry, 67(2), 139-145.

Agin-Liebes, G. I., Malone, T., Yalch, M. M., Mennenga, S. E., Ponté, K. L., Guss, J., . . . Ross, S. (2020). Long-term follow-up of psilocybin-assisted psychotherapy for psychiatric and existential distress in patients with life-threatening cancer. Journal of Psychopharmacology, 34(2), 155-166.

Alberich, S., Martinez-Cengotitabengoa, M., Lopez, P., Zorrilla, I., Nunez, N., Vieta, E., & Gonzalez-Pinto, A. (2017). Efficacy and safety of ketamine in bipolar depression: A systematic review. Rev Psiquiatr Salud Ment, 10(2), 104-112. (Eficacia y seguridad de la ketamina en depresion bipolar: una revision sistematica.)

Albott, C. S., Lim, K. O., Forbes, M. K., Erbes, C., Tye, S. J., Grabowski, J. G., . . . Shiroma, P. R. (2018). Efficacy, Safety, and Durability of Repeated Ketamine Infusions for Comorbid Posttraumatic Stress Disorder and Treatment-Resistant Depression. J Clin Psychiatry, 79(3).

Anderson, B. T., Danforth, A., Daroff, P. R., Stauffer, C., Ekman, E., Agin-Liebes, G., . . . Woolley, J. (2020). Psilocybin-assisted group therapy for demoralized older long-term AIDS survivor men: An open-label safety and feasibility pilot study. EClinicalMedicine, 27, 100538.

Azhari, N., Hu, H., O'Malley, K. Y., Blocker, M. E., Levin, F. R., & Dakwar, E. (2021). Ketamine-facilitated behavioral treatment for cannabis use disorder: A proof of concept study. Am J Drug Alcohol Abuse, 47(1), 92-97.

Bartoli, F., Riboldi, I., Crocamo, C., Di Brita, C., Clerici, M., & Carra, G. (2017). Ketamine as a rapid-acting agent for suicidal ideation: A meta-analysis. Neurosci Biobehav Rev, 77, 232-236.

Bedi, G., Cecchi, G. A., Slezak, D. F., Carrillo, F., Sigman, M., & de Wit, H. (2014). A window into the intoxicated mind? Speech as an index of psychoactive drug effects. Neuropsychopharmacology, 39(10), 2340-2348.

Bogenschutz, M. P., Forcehimes, A. A., Pommy, J. A., Wilcox, C. E., Barbosa, P. C., & Strassman, R. J. (2015). Psilocybin-assisted treatment for alcohol dependence: a proof-of-concept study. Journal of psychopharmacology (Oxford, England), 29(3), 289-299.

Brewerton, T. D., Lafrance, A., & Mithoefer, M. C. (2021). The potential use of N-methyl-3,4-methylenedioxyamphetamine (MDMA) assisted psychotherapy in the treatment of eating disorders comorbid with PTSD. Med Hypotheses, 146, 110367.

Caddy, C., Amit, B. H., McCloud, T. L., Rendell, J. M., Furukawa, T. A., McShane, R., . . . Cipriani, A. (2015). Ketamine and other glutamate receptor modulators for depression in adults. Cochrane Database Syst Rev(9), CD011612.

Caddy, C., Giaroli, G., White, T. P., Shergill, S. S., & Tracy, D. K. (2014). Ketamine as the prototype glutamatergic antidepressant: pharmacodynamic actions, and a systematic review and meta-analysis of efficacy. Ther Adv Psychopharmacol, 4(2), 75-99.

Carhart-Harris, R. L., Bolstridge, M., Day, C. M. J., Rucker, J., Watts, R., Erritzoe, D. E., . . . Nutt, D. J. (2018). Psilocybin with psychological support for treatment-resistant depression: six-month follow-up. Psychopharmacology (Berl), 235(2), 399-408.

Carhart-Harris, R. L., Bolstridge, M., Rucker, J., Day, C. M. J., Erritzoe, D., Kaelen, M., . . . Nutt, D. J. (2016). Psilocybin with psychological support for treatment-resistant depression: An open-label feasibility study. The Lancet Psychiatry, 3(7), 619-627.

Carhart-Harris, R. L., Wall, M. B., Erritzoe, D., Kaelen, M., Ferguson, B., De Meer, I., . . . Nutt, D. J. (2014). The effect of acutely administered MDMA on subjective and BOLD-fMRI responses to favourite and worst autobiographical memories. Int J Neuropsychopharmacol, 17(4), 527-540.

Covvey, J. R., Crawford, A. N., & Lowe, D. K. (2012). Intravenous ketamine for treatment-resistant major depressive disorder. Ann Pharmacother, 46(1), 117-123.

Coyle, C. M., & Laws, K. R. (2015). The use of ketamine as an antidepressant: a systematic review and meta-analysis. Hum Psychopharmacol, 30(3), 152-163.

D'Anci, K. E., & Uhl, S. (2020). Treatments for the Prevention and Management of Suicide. Ann Intern Med, 172(2), 168.

Dadiomov, D., & Lee, K. (2019). The effects of ketamine on suicidality across various formulations and study settings. Ment Health Clin, 9(1), 48-60.

Dakwar, E., Anerella, C., Hart, C. L., Levin, F. R., Mathew, S. J., & Nunes, E. V. (2014). Therapeutic infusions of ketamine: do the psychoactive effects matter? Drug Alcohol Depend, 136, 153-157.

Dakwar, E., Hart, C. L., Levin, F. R., Nunes, E. V., & Foltin, R. W. (2017). Cocaine self-administration disrupted by the N-methyl-D-aspartate receptor antagonist ketamine: a randomized, crossover trial. Mol Psychiatry, 22(1), 76-81.

Dakwar, E., Levin, F., Foltin, R. W., Nunes, E. V., & Hart, C. L. (2014). The effects of subanesthetic ketamine infusions on motivation to quit and cue-induced craving in cocaine-dependent research volunteers. Biol Psychiatry, 76(1), 40-46.

Dakwar, E., Levin, F., Hart, C. L., Basaraba, C., Choi, J., Pavlicova, M., & Nunes, E. V. (2020). A Single Ketamine Infusion Combined With Motivational Enhancement Therapy for Alcohol Use Disorder: A Randomized Midazolam-Controlled Pilot Trial. Am J Psychiatry, 177(2), 125-133.

Dakwar, E., Nunes, E. V., Hart, C. L., Foltin, R. W., Mathew, S. J., Carpenter, K. M., . . . Levin, F. R. (2019). A Single Ketamine Infusion Combined With Mindfulness-Based Behavioral Modification to Treat Cocaine Dependence: A Randomized Clinical Trial. Am J Psychiatry, 176(11), 923-930.

Dakwar, E., Nunes, E. V., Hart, C. L., Hu, M. C., Foltin, R. W., & Levin, F. R. (2018). A sub-set of psychoactive effects may be critical to the behavioral impact of ketamine on cocaine use disorder: Results from a randomized, controlled laboratory study. Neuropharmacology, 142, 270-276.

Danforth, A. L., Grob, C. S., Struble, C., Feduccia, A. A., Walker, N., Jerome, L., . . . Emerson, A. (2018). Reduction in social anxiety after MDMA-assisted psychotherapy with autistic adults: a randomized, double-blind, placebo-controlled pilot study. Psychopharmacology (Berl), 235(11), 3137-3148.

Dore, J., Turnipseed, B., Dwyer, S., Turnipseed, A., Andries, J., Ascani, G., . . . Wolfson, P. (2019). Ketamine Assisted Psychotherapy (KAP): Patient Demographics, Clinical Data and Outcomes in Three Large Practices Administering Ketamine with Psychotherapy. J Psychoactive Drugs, 51(2), 189-198.

Feder, A., Parides, M. K., Murrough, J. W., Perez, A. M., Morgan, J. E., Saxena, S., . . . Charney, D. S. (2014). Efficacy of intravenous ketamine for treatment of chronic posttraumatic stress disorder: a randomized clinical trial. JAMA Psychiatry, 71(6), 681-688.

Feduccia, A. A., Holland, J., & Mithoefer, M. C. (2018). Progress and promise for the MDMA drug development program. Psychopharmacology (Berl), 235(2), 561-571.

Feduccia, A. A., Jerome, L., Yazar-Klosinski, B., Emerson, A., Mithoefer, M. C., & Doblin, R. (2019). Breakthrough for Trauma Treatment: Safety and Efficacy of MDMA-Assisted Psychotherapy Compared to Paroxetine and Sertraline. Front Psychiatry, 10, 650.

Fond, G., Loundou, A., Rabu, C., Macgregor, A., Lancon, C., Brittner, M., . . . Boyer, L. (2014). Ketamine administration in depressive disorders: a systematic review and meta-analysis. Psychopharmacology (Berl), 231(18), 3663-3676.

Fornaro, M., Carvalho, A. F., Fusco, A., Anastasia, A., Solmi, M., Berk, M., . . . de Bartolomeis, A. (2020). The concept and management of acute episodes of treatment-resistant bipolar disorder: a systematic review and exploratory meta-analysis of randomized controlled trials. J Affect Disord, 276, 970-983.

Garay, R. P., Zarate, C. A., Jr., Charpeaud, T., Citrome, L., Correll, C. U., Hameg, A., & Llorca, P. M. (2017). Investigational drugs in recent clinical trials for treatment-resistant depression. Expert Rev Neurother, 17(6), 593-609.

Glue, P., Neehoff, S. M., Medlicott, N. J., Gray, A., Kibby, G., & McNaughton, N. (2018). Safety and efficacy of maintenance ketamine treatment in patients with treatment-refractory generalised anxiety and social anxiety disorders. Journal of psychopharmacology (Oxford, England), 32(6), 663-667.

Griffiths, R. R., Johnson, M. W., Richards, W. A., Richards, B. D., McCann, U., & Jesse, R. (2011). Psilocybin occasioned mystical-type experiences: immediate and persisting dose-related effects. Psychopharmacology (Berl), 218(4), 649-665.

Grob, C. S., Danforth, A. L., Chopra, G. S., Hagerty, M., McKay, C. R., Halberstadt, A. L., & Greer, G. R. (2011). Pilot study of psilocybin treatment for anxiety in patients with advanced-stage cancer. Arch Gen Psychiatry, 68(1), 71-78.

Han, Y., Chen, J., Zou, D., Zheng, P., Li, Q., Wang, H., . . . Xie, P. (2016). Efficacy of ketamine in the rapid treatment of major depressive disorder: a meta-analysis of randomized, double-blind, placebo-controlled studies. Neuropsychiatr Dis Treat, 12, 2859-2867.

Hasselmann, H. W. (2014). Ketamine as antidepressant? Current state and future perspectives. Curr Neuropharmacol, 12(1), 57-70.

Jerome, L., Feduccia, A. A., Wang, J. B., Hamilton, S., Yazar-Klosinski, B., Emerson, A., . . . Doblin, R. (2020). Long-term follow-up outcomes of MDMA-assisted psychotherapy for treatment of PTSD: a longitudinal pooled analysis of six phase 2 trials. Psychopharmacology (Berl), 237(8), 2485-2497.

Johnson, M. W., Garcia-Romeu, A., Cosimano, M. P., & Griffiths, R. R. (2014). Pilot study of the 5-HT2AR agonist psilocybin in the treatment of tobacco addiction. Journal of psychopharmacology (Oxford, England), 28(11), 983-992.

Johnson, M. W., Garcia-Romeu, A., & Griffiths, R. R. (2017). Long-term follow-up of psilocybin-facilitated smoking cessation. Am J Drug Alcohol Abuse, 43(1), 55-60.

Jovaisa, T., Laurinenas, G., Vosylius, S., Sipylaite, J., Badaras, R., & Ivaskevicius, J. (2006). Effects of ketamine on precipitated opiate withdrawal. Medicina (Kaunas), 42(8), 625-634.

Katalinic, N., Lai, R., Somogyi, A., Mitchell, P. B., Glue, P., & Loo, C. K. (2013). Ketamine as a new treatment for depression: a review of its efficacy and adverse effects. Aust N Z J Psychiatry, 47(8), 710-727.

Kishimoto, T., Chawla, J. M., Hagi, K., Zarate, C. A., Kane, J. M., Bauer, M., & Correll, C. U. (2016). Single-dose infusion ketamine and non-ketamine N-methyl-d-aspartate receptor antagonists for unipolar and bipolar depression: a meta-analysis of efficacy, safety and time trajectories. Psychol Med, 46(7), 1459-1472.

Kleeblatt, J., Betzler, F., Kilarski, L. L., Bschor, T., & Kohler, S. (2017). Efficacy of off-label augmentation in unipolar depression: A systematic review of the evidence. Eur Neuropsychopharmacol, 27(5), 423-441.

Kohtala, S. (2021). Ketamine-50 years in use: from anesthesia to rapid antidepressant effects and neurobiological mechanisms. Pharmacol Rep, 73(2), 323-345.

Kolar, D. (2018). Addictive potential of novel treatments for refractory depression and anxiety. Neuropsychiatr Dis Treat, 14, 1513-1519.

Kraus, C., Rabl, U., Vanicek, T., Carlberg, L., Popovic, A., Spies, M., . . . Kasper, S. (2017). Administration of ketamine for unipolar and bipolar depression. Int J Psychiatry Clin Pract, 21(1), 2-12.

Krupitsky, E., Burakov, A., Romanova, T., Dunaevsky, I., Strassman, R., & Grinenko, A. (2002). Ketamine psychotherapy for heroin addiction: immediate effects and two-year follow-up. J Subst Abuse Treat, 23(4), 273-283.

Krupitsky, E. M., Burakov, A. M., Dunaevsky, I. V., Romanova, T. N., Slavina, T. Y., & Grinenko, A. Y. (2007). Single versus repeated sessions of ketamine-assisted psychotherapy for people with heroin dependence. J Psychoactive Drugs, 39(1), 13-19.

Krupitsky, E. M., Grineko, A. Y., Berkaliev, T. N., Paley, A. I., Tetrov, U. N., Mushkov, K. A., & Borodikin, Y. S. (1992). The Combination of Psychedelic and Aversive Approaches in Alcoholism Treatment. Alcoholism Treatment Quarterly, 9(1), 99-105.

Krupitsky, E. M., & Grinenko, A. Y. (1997). Ketamine psychedelic therapy (KPT): a review of the results of ten years of research. J Psychoactive Drugs, 29(2), 165-183.

Lee, E. E., Della Selva, M. P., Liu, A., & Himelhoch, S. (2015). Ketamine as a novel treatment for major depressive disorder and bipolar depression: a systematic review and quantitative meta-analysis. Gen Hosp Psychiatry, 37(2), 178-184.

MAPS. (2021). MDMA Investigator Brochure.

Mathai, D. S., Meyer, M. J., Storch, E. A., & Kosten, T. R. (2020). The relationship between subjective effects induced by a single dose of ketamine and treatment response in patients with major depressive disorder: A systematic review. J Affect Disord, 264, 123-129.

McCloud, T. L., Caddy, C., Jochim, J., Rendell, J. M., Diamond, P. R., Shuttleworth, C., . . . Cipriani, A. (2015). Ketamine and other glutamate receptor modulators for depression in bipolar disorder in adults. Cochrane Database Syst Rev(9), CD011611.

McGirr, A., & Berlim, M. T. (2014). A comment on Fond and colleagues' systematic review and meta-analysis of ketamine in the treatment of depressive disorders (Psychopharmacology 2014; Jul 20 [Epub ahead of print]). Psychopharmacology (Berl), 231(19), 3907-3908.

Mitchell, J. M., Bogenschutz, M., Lilienstein, A., Harrison, C., Kleiman, S., Parker-Guilbert, K., . . . Doblin, R. (2021). MDMA-assisted therapy for severe PTSD: a randomized, double-blind, placebo-controlled phase 3 study. Nat Med, 27(6), 1025-1033.

Mithoefer, M. C., Feduccia, A. A., Jerome, L., Mithoefer, A., Wagner, M., Walsh, Z., . . . Doblin, R. (2019). MDMA-assisted psychotherapy for treatment of PTSD: study design and rationale for phase 3 trials based on pooled analysis of six phase 2 randomized controlled trials. Psychopharmacology (Berl), 236(9), 2735-2745.

Moreno, F. A., Wiegand, C. B., Taitano, E. K., & Delgado, P. L. (2006). Safety, tolerability, and efficacy of psilocybin in 9 patients with obsessive-compulsive disorder. Journal of Clinical Psychiatry, 67(11), 1735-1740.

Papadimitropoulou, K., Vossen, C., Karabis, A., Donatti, C., & Kubitz, N. (2017). Comparative efficacy and tolerability of pharmacological and somatic interventions in adult patients with treatment-resistant depression: a systematic review and network meta-analysis. Curr Med Res Opin, 33(4), 701-711.

Papakostas, G. I. (2020). Happiness and Treatment Outcome in Resistant Depression. J Clin Psychiatry, 81(6).

Pizon, A. F., Lynch, M. J., Benedict, N. J., Yanta, J. H., Frisch, A., Menke, N. B., . . . Kane-Gill, S. L. (2018). Adjunct Ketamine Use in the Management of Severe Ethanol Withdrawal. Crit Care Med, 46(8), e768-e771.

Reiche, S., Hermle, L., Gutwinski, S., Jungaberle, H., Gasser, P., & Majic, T. (2018). Serotonergic hallucinogens in the treatment of anxiety and depression in patients suffering from a life-threatening disease: A systematic review. Prog Neuropsychopharmacol Biol Psychiatry, 81, 1-10.

Reinstatler, L., & Youssef, N. A. (2015). Ketamine as a potential treatment for suicidal ideation: a systematic review of the literature. Drugs R D, 15(1), 37-43.

Robison, R., Brendle, M., Moore, C., Cross, H., Helm, L., Darling, S., Thayer, S., Thielking, P., & Shannon, S. (2023). Ketamine-Assisted Group Psychotherapy for Frontline Healthcare Workers with COVID-19-Related Burnout and PTSD: A Case Series of Effectiveness/Safety for 10 Participants. Journal of psychoactive drugs, 1–10. Advance online publication.

Rodriguez, C. I., Kegeles, L. S., Levinson, A., Feng, T., Marcus, S. M., Vermes, D., . . . Simpson, H. B. (2013). Randomized controlled crossover trial of ketamine in obsessive-compulsive disorder: proof-of-concept. Neuropsychopharmacology, 38(12), 2475-2483.

Romeo, B., Choucha, W., Fossati, P., & Rotge, J. Y. (2015). Meta-analysis of short- and mid-term efficacy of ketamine in unipolar and bipolar depression. Psychiatry Res, 230(2), 682-688.

Ross, C., Jain, R., Bonnett, C. J., & Wolfson, P. (2019). High-dose ketamine infusion for the treatment of posttraumatic stress disorder in combat veterans. Ann Clin Psychiatry, 31(4), 271-279.

Rothberg, R. L., Azhari, N., Haug, N. A., & Dakwar, E. (2021). Mystical-type experiences occasioned by ketamine mediate its impact on at-risk drinking: Results from a randomized, controlled trial. Journal of psychopharmacology (Oxford, England), 35(2), 150-158.

Schindler, E. A. D., Sewell, R. A., Gottschalk, C. H., Luddy, C., Flynn, L. T., Lindsey, H., . . . D'Souza, D. C. (2021). Exploratory Controlled Study of the Migraine-Suppressing Effects of Psilocybin. Neurotherapeutics, 18(1), 534-543.

Serafini, G., Howland, R. H., Rovedi, F., Girardi, P., & Amore, M. (2014). The role of ketamine in treatment-resistant depression: a systematic review. Curr Neuropharmacol, 12(5), 444-461.

Sessa, B., Sakal, C., O'Brien, S., & Nutt, D. (2019). First study of safety and tolerability of 3,4-methylenedioxymethamphetamine (MDMA)-assisted psychotherapy in patients with alcohol use disorder: preliminary data on the first four participants. BMJ Case Rep, 12(7).

Shadli, S. M., Kawe, T., Martin, D., McNaughton, N., Neehoff, S., & Glue, P. (2018). Ketamine Effects on EEG during Therapy of Treatment-Resistant Generalized Anxiety and Social Anxiety. Int J Neuropsychopharmacol, 21(8), 717-724.

Shah, P., McDowell, M., Ebisu, R., Hanif, T., & Toerne, T. (2018). Adjunctive Use of Ketamine for Benzodiazepine-Resistant Severe Alcohol Withdrawal: a Retrospective Evaluation. J Med Toxicol, 14(3), 229-236.

Studerus, E., Gamma, A., Kometer, M., & Vollenweider, F. X. (2012). Prediction of psilocybin response in healthy volunteers. PLOS ONE, 7(2), e30800.

Usona Institute. (2021). Investigator's Brochure; Psilocybin.

Wardle, M. C., & de Wit, H. (2014). MDMA alters emotional processing and facilitates positive social interaction. Psychopharmacology (Berl), 231(21), 4219-4229.

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. Soc Cogn Affect Neurosci, 9(8), 1076-1081.

Wilkinson, S. T., Ballard, E. D., Bloch, M. H., Mathew, S. J., Murrough, J. W., Feder, A., . . . Sanacora, G. (2018). The Effect of a Single Dose of Intravenous Ketamine on Suicidal Ideation: A Systematic Review and Individual Participant Data Meta-Analysis. Am J Psychiatry, 175(2), 150-158.

Witt, K., Potts, J., Hubers, A., Grunebaum, M. F., Murrough, J. W., Loo, C., . . . Hawton, K. (2020). Ketamine for suicidal ideation in adults with psychiatric disorders: A systematic review and meta-analysis of treatment trials. Aust N Z J Psychiatry, 54(1), 29-45.

Wolfson, P. E., Andries, J., Feduccia, A. A., Jerome, L., Wang, J. B., Williams, E., . . . Doblin, R. (2020). MDMA-assisted psychotherapy for treatment of anxiety and other psychological distress related to life-threatening illnesses: a randomized pilot study. Sci Rep, 10(1), 20442.

Zheng, W., Zhou, Y. L., Wang, C. Y., Lan, X. F., Zhang, B., Zhou, S. M., . . . Ning, Y. P. (2020). Association between plasma levels of BDNF and the antisuicidal effects of repeated ketamine infusions in depression with suicidal ideation. Ther Adv Psychopharmacol, 10, 2045125320973794.