Psychedelic Therapy

Last Updated: September 20, 2023

Psychedelic therapy provides psychedelic drugs (e.g., psilocybin, ayahuasca, LSD) in a controlled setting where professional psychotherapy is used to both prepare for and integrate the psychedelic experience. Psychedelic therapy shows promise for the treatment of mental health conditions including depression, anxiety, and substance use disorders.

Psychedelic Therapy is most often used for

What is psychedelic therapy?

Psychedelic therapy is the use of psychedelic medications along with psychological support to improve quality of life and functioning. The word “psychedelic” is derived from the Greek words psychē (the mind/soul) and dēlos (to reveal), and psychedelics have a long history of traditional use for their “mind-revealing” effects.[4] Psychedelic therapy uses “classic psychedelics” like psilocybin (most commonly found in certain species of mushroom), lysergic acid diethylamide (LSD), and N,N-dimethyltryptamine (DMT) (found in ayahuasca), with most current research using psilocybin.[5] Psychedelic therapy research is rapidly expanding, but it is still considered to be in the early stages and public access to psychedelic therapy is limited. Additionally, psychedelics are still illegal in many regions of the world.

Psychedelic therapy generally consists of three phases: preparation, the psychedelic session, and integration. During the preparation phase, the person receiving treatment works with a health practitioner and/or mental health professional to learn about the psychedelic medication, discuss expectations, and set intentions for the experience. During the psychedelic session, the medication is administered in a safe and comfortable environment where the person can be monitored and supported if needed. Afterward, the integration phase provides an opportunity to debrief, reflect on, and integrate the experience. Therapy sessions using various models of support are often provided during the preparatory and integration phases, and in some studies, the psychedelic session is repeated after several weeks.[3][6]

What are psychedelic therapy’s main benefits?

Psychedelic therapy seems to be a promising tool for the management of mental health conditions including depression,[3][1][7][2] anxiety,[7][2] and substance use disorders[8][9][10] (primarily alcohol and tobacco use disorders). Currently, the strongest evidence exists for depression and anxiety, including difficult-to-treat conditions like treatment-resistant depression (when two different antidepressants have failed to work) and depression/anxiety related to major illnesses (e.g., terminal cancer).[3] Even in people with no apparent mental or physical diseases, psychedelic therapy has demonstrated long-term (>1 year) improvements in well-being.[11][12] The vast majority of research has been done using psilocybin, although ayahuasca and LSD have also been studied with seemingly comparable efficacy.[2]

A major benefit of psychedelic therapy is the minimal dosing required to achieve a therapeutic effect. Unlike antidepressants, which need to be dosed daily and can take upwards of 4 weeks to begin to work, a single psychedelic session has been found to improve depression and anxiety symptoms rapidly (in some studies within 1 day), with effects potentially lasting 6 months or longer.[13] While positive effects have been consistently shown after a single session, there is some evidence to suggest that two psychedelic sessions produces better results.[2]

What are psychedelic therapy’s main drawbacks?

Current research suggests that, with proper screening protocols (e.g., the exclusion of people with a personal or family history of psychosis), psychedelic therapy is quite safe. Although side effects can occur during the psychedelic session, they are generally short-term and resolve soon after the medication’s effects have worn off; these include anxiety, nausea, vomiting (particularly in the case of ayahuasca), headache, and mild increases in blood pressure and heart rate.[3][5]

Psychedelics produce profound short-term psychological effects when consumed in full doses, including changes in thinking, perception, sense of self, and emotions (positive and negative) that may lead to mystical/spiritual experiences and an increased sense of social connectedness. While these “side effects” might be uncomfortable for some people, they are suggested to be an important component of the therapeutic effect of psychedelic therapy.[5]

A rare possible side effect that has been identified in case reports is hallucinogen persisting perception disorder (HPPD), which is when perceptual disturbances experienced while under the influence of psychoactive drugs (e.g., classic psychedelics, cannabis, MDMA) re-emerge after the drug's effects have worn off. This might include visual “flashbacks” or other disturbances like visual snow (grainy, pixelated vision) or floaters. HPPD has not been reported in any psychedelic therapy studies and the true risk is not clear.[14][11]

How does psychedelic therapy work?

The mechanisms underpinning psychedelic therapy’s effects are being actively researched, but they likely involve a combination of psychological and biological changes. Psychologically, psychedelic therapy seems to increase insight, enhance emotional processing, and promote psychological flexibility (the ability to adapt our thoughts, emotions, and behaviors when faced with challenging or new situations).[3] This could create an opportunity to shift negative core beliefs and maladaptive thought patterns.[5] Interestingly, having a spiritual or mystical experience during the psychedelic session has repeatedly been found to predict a sustained psychological benefit.[5][11] This can be assessed by researchers using a questionnaire and generally involves positive feelings of oneness/interconnectedness with the world and an intuitive understanding of some aspect of life.[11]

At a biological level, psychedelic therapy may induce structural and functional changes in the brain. Classic psychedelics primarily activate serotonin 2A (5-HT2A) receptors in the brain, which produces an altered state of consciousness and also seems to activate neurobiological pathways that lead to changes in neuroplasticity—the ability of the brain to change in both structure and function. Preclinical trials in mice have found that a single dose of psychedelics increases the expression of genes and proteins related to plasticity, including brain-derived neurotrophic factor (BDNF); induces cellular changes (the density/number of neurons and dendrites); and increases learning behaviors. Only a few studies have been performed in humans and the results are less clear, but preliminary neuroimaging studies report shifts in functional connectivity that are sustained after the drug has worn off.[15][16] For a deeper dive into these mechanisms, check out our study summary.

What are other names for Psychedelic Therapy?
Note that Psychedelic Therapy is also known as:
  • Psychedelic-Assisted Therapy
  • Psychedelic-Assisted Psychotherapy
Dosage information

There is a high level of variability between studies when it comes to the type and frequency of therapy sessions provided; the psychedelic medication type, dosage, and frequency; and the environment provided for the psychedelic sessions. Currently, the optimal psychedelic therapy protocol is not clear.

Most research has used psilocybin in dosages ranging from 20–45 mg per dose, either taken only once or taken twice with a separation of at least seven days between doses. Preliminary research suggests that protocols using higher doses (≥30 mg)[1] and two psychedelic sessions[2] may have better effects, although further research is needed to validate these findings. LSD is most commonly given as an oral dose of 200 μg, and ayahuasca dosing, while not well-defined, is generally based on weight and DMT content.[3]

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Update History
2023-09-20 00:30:02

Database updated


A handful of new meta-analyses were added to the database for this page.

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2023-09-12 00:30:03

Page with FAQs and database created


We created this page, and populated the FAQs and database references with the newest literature on the subject.

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  1. ^Nan-Xi Li, Yi-Ru Hu, Wang-Ni Chen, Bin ZhangDose effect of psilocybin on primary and secondary depression: a preliminary systematic review and meta-analysisJ Affect Disord.(2021 Sep 17)
  2. ^Robert F Leger, Ellen M UnterwaldAssessing the effects of methodological differences on outcomes in the use of psychedelics in the treatment of anxiety and depressive disorders: A systematic review and meta-analysisJ Psychopharmacol.(2021 Sep 14)
  3. ^Ko K, Kopra EI, Cleare AJ, Rucker JJPsychedelic therapy for depressive symptoms: A systematic review and meta-analysis.J Affect Disord.(2023-Feb-01)
  4. ^Carhart-Harris RL, Goodwin GMThe Therapeutic Potential of Psychedelic Drugs: Past, Present, and Future.Neuropsychopharmacology.(2017-Oct)
  5. ^Rosenblat JD, Husain MI, Lee Y, McIntyre RS, Mansur RB, Castle D, Offman H, Parikh SV, Frey BN, Schaffer A, Greenway KT, Garel N, Beaulieu S, Kennedy SH, Lam RW, Milev R, Ravindran AV, Tourjman V, Ameringen MV, Yatham LN, Taylor VThe Canadian Network for Mood and Anxiety Treatments (CANMAT) Task Force Report: Serotonergic Psychedelic Treatments for Major Depressive Disorder.Can J Psychiatry.(2023-Jan)
  6. ^David M Horton, Blaise Morrison, Judy SchmidtSystematized Review of Psychotherapeutic Components of Psilocybin-Assisted PsychotherapyAm J Psychother.(2021 Jul 23)
  7. ^Simon B Goldberg, Brian T Pace, Christopher R Nicholas, Charles L Raison, Paul R HutsonThe experimental effects of psilocybin on symptoms of anxiety and depression: A meta-analysisPsychiatry Res.(2020 Feb)
  8. ^van der Meer PB, Fuentes JJ, Kaptein AA, Schoones JW, de Waal MM, Goudriaan AE, Kramers K, Schellekens A, Somers M, Bossong MG, Batalla ATherapeutic effect of psilocybin in addiction: A systematic review.Front Psychiatry.(2023)
  9. ^Bogenschutz MP, Ross S, Bhatt S, Baron T, Forcehimes AA, Laska E, Mennenga SE, O'Donnell K, Owens LT, Podrebarac S, Rotrosen J, Tonigan JS, Worth LPercentage of Heavy Drinking Days Following Psilocybin-Assisted Psychotherapy vs Placebo in the Treatment of Adult Patients With Alcohol Use Disorder: A Randomized Clinical Trial.JAMA Psychiatry.(2022-Oct-01)
  10. ^Krebs TS, Johansen PØLysergic acid diethylamide (LSD) for alcoholism: meta-analysis of randomized controlled trials.J Psychopharmacol.(2012-Jul)
  11. ^Aday JS, Mitzkovitz CM, Bloesch EK, Davoli CC, Davis AKLong-term effects of psychedelic drugs: A systematic review.Neurosci Biobehav Rev.(2020-Jun)
  12. ^Goldberg SB, Shechet B, Nicholas CR, Ng CW, Deole G, Chen Z, Raison CLPost-acute psychological effects of classical serotonergic psychedelics: a systematic review and meta-analysis.Psychol Med.(2020-Dec)
  13. ^Bruno Romeo, Laurent Karila, Catherine Martelli, Amine BenyaminaEfficacy of psychedelic treatments on depressive symptoms: A meta-analysisJ Psychopharmacol.(2020 Oct)
  14. ^Ford H, Fraser CL, Solly E, Clough M, Fielding J, White O, Van Der Walt AHallucinogenic Persisting Perception Disorder: A Case Series and Review of the Literature.Front Neurol.(2022)
  15. ^Cato M H de Vos, Natasha L Mason, Kim P C KuypersPsychedelics and Neuroplasticity: A Systematic Review Unraveling the Biological Underpinnings of PsychedelicsFront Psychiatry.(2021 Sep 10)
  16. ^Frederick S Barrett, Manoj K Doss, Nathan D Sepeda, James J Pekar, Roland R GriffithsEmotions and brain function are altered up to one month after a single high dose of psilocybinSci Rep.(2020 Feb 10)
  17. ^Nichols DE, Walter HThe History of Psychedelics in Psychiatry.Pharmacopsychiatry.(2021-Jul)
  18. ^Henry Lowe, Ngeh Toyang, Blair Steele, Henkel Valentine, Justin Grant, Amza Ali, Wilfred Ngwa, Lorenzo GordonThe Therapeutic Potential of PsilocybinMolecules.(2021 May 15)
  19. ^Gonzalez D, Cantillo J, Perez I, Carvalho M, Aronovich A, Farre M, Feilding A, Obiols JE, Bouso JCThe Shipibo Ceremonial Use of Ayahuasca to Promote Well-Being: An Observational Study.Front Pharmacol.(2021)
  20. ^Perkins D, Opaleye ES, Simonova H, Bouso JC, Tófoli LF, GalvÃo-Coelho NL, Schubert V, Sarris JAssociations between ayahuasca consumption in naturalistic settings and current alcohol and drug use: Results of a large international cross-sectional survey.Drug Alcohol Rev.(2022-Jan)
Examine Database References
  1. Alcohol Dependence Symptoms - Krebs TS, Johansen PØLysergic acid diethylamide (LSD) for alcoholism: meta-analysis of randomized controlled trials.J Psychopharmacol.(2012-Jul)
  2. Depression Symptoms - Simon B Goldberg, Brian T Pace, Christopher R Nicholas, Charles L Raison, Paul R HutsonThe experimental effects of psilocybin on symptoms of anxiety and depression: A meta-analysisPsychiatry Res.(2020 Feb)
  3. Depression Symptoms - Ko K, Kopra EI, Cleare AJ, Rucker JJPsychedelic therapy for depressive symptoms: A systematic review and meta-analysis.J Affect Disord.(2023-Feb-01)
  4. Suicidal Thoughts - Zeifman RJ, Yu D, Singhal N, Wang G, Nayak SM, Weissman CRDecreases in Suicidality Following Psychedelic Therapy: A Meta-Analysis of Individual Patient Data Across Clinical Trials.J Clin Psychiatry.(2022-Jan-18)