A qualitative and quantitative account of patient’s experiences of ketamine and its antidepressant properties
In 32 people with major depressive disorder given subanaesthetic ketamine versus an active placebo, larger 24‑hour antidepressant responses correlated with psychedelic dimensions (spirituality, unity, insight) and qualitative interviews documented pervasive perceptual changes, loss of control, emotional shifts and a lasting afterglow that altered perspectives on life and treatment. These findings give preliminary evidence that the acute psychedelic experience and afterglow contribute to ketamine’s antidepressant effects and that common questionnaires may not fully capture its phenomenology.
Authors
- Suresh Muthukumaraswamy
- Meg Spriggs
- Rebecca Sumner
Published
Abstract
Background
Ketamine is central to one of the most rapidly growing areas of neuroscientific research into novel treatments for depression. Limited research has indicated that the psychedelic properties of ketamine may play a role in its antidepressant effects.
Aim
The aim of the current study was to explore the psychedelic experiences and sustained impact of ketamine in major depressive disorder.
Methods
In the current study, ketamine (0.44 mg/kg) was administered to 32 volunteers with major depressive disorder in a crossover design with the active-placebo remifentanil, in a magnetic resonance imaging (MRI) environment. The 11-dimension altered states of consciousness questionnaire and individual qualitative interviews were used to capture the acute psychedelic experience. The Montgomery-Asberg Depression Rating Scale and further interviewing explored lasting effects. The second qualitative interview took place ⩾3 weeks post-ketamine.
Results
Greater antidepressant response (reduction in Montgomery-Asberg Depression Rating Scale at 24 h) correlated with the 11-dimension altered states of consciousness dimensions: spirituality, experience of unity, and insight. The first qualitative interview revealed that all participants experienced perceptual changes. Additional themes emerged including loss of control and emotional and mood changes. The final interview showed evidence of a psychedelic afterglow, and changes to perspective on life, people, and problems, as well as changes to how participants felt about their depression and treatments.
Conclusions
The current study provides preliminary evidence for a role of the psychedelic experience and afterglow in ketamine’s antidepressant properties. Reflexive thematic analysis provided a wealth of information on participants’ experience of the study and demonstrated the psychedelic properties of ketamine are not fully captured by commonly used questionnaires.
Research Summary of 'A qualitative and quantitative account of patient’s experiences of ketamine and its antidepressant properties'
Introduction
Ketamine has emerged as a prominent investigational treatment for rapid-acting antidepressant effects. Earlier clinical work showed rapid symptom reduction in treatment‑resistant depression and, because ketamine produces acute alterations in consciousness, researchers have queried whether the psychedelic properties of ketamine contribute to its antidepressant action. Compared with classic serotonergic psychedelics such as psilocybin, ketamine differs in pharmacology and phenomenology, and prior studies relating ketamine's acute subjective effects to clinical benefit have been inconsistent, in part because typical scales (for example, CADSS or BPRS) emphasise dissociation or psychotomimesis rather than the richer, mystical-like features measured by instruments such as the Altered States of Consciousness (ASC) questionnaire. Sumner and colleagues designed a mixed-methods study to explore the acute psychedelic experience of sub‑anesthetic ketamine and its association with antidepressant response, and to characterise any sustained changes in perspective or mood that persist beyond the immediate therapeutic window. The study combined quantitative measurement using the 11‑dimension ASC (11D‑ASC) and clinician-rated depression scores with two rounds of qualitative interviews conducted shortly after infusion and 3–8 weeks later, using a randomised, double‑blind, active placebo–controlled crossover framework against remifentanil.
Expert Research Summaries
Go Pro to access AI-powered section-by-section summaries, editorial takes, and the full research toolkit.
Study Details
- Study Typeindividual
- Journal
- Compound
- Topics
- Authors
- APA Citation
Sumner, R. L., Chacko, E., McMillan, R., Spriggs, M. J., Anderson, C., Chen, J., French, A., Jung, S., Rajan, A., Malpas, G., Hay, J., Ponton, R., Muthukumaraswamy, S. D., & Sundram, F. (2021). A qualitative and quantitative account of patient’s experiences of ketamine and its antidepressant properties. Journal of Psychopharmacology, 35(8), 946-961. https://doi.org/10.1177/0269881121998321
References (33)
Papers cited by this study that are also in Blossom
Barrett, F. S., Bradstreet, M. P., Leoutsakos, J. M. S. et al. · Journal of Psychopharmacology (2016)
Barrett, F. S., Johnson, M. W., Griffiths, R. R. · Journal of Psychopharmacology (2015)
Berman, R. M., Cappiello, A., Anand, A. et al. · Biological Psychiatry (2000)
Bowdle, A. T., Radant, A. D., Cowley, D. S. et al. · Anesthesiology (1998)
Carhart-Harris, R. L., Erritzoe, D., Williams, T. et al. · PNAS (2012)
Carhart-Harris, R. L., Friston, K. J. · Pharmacological Reviews (2019)
Carhart-Harris, R. L., Leech, R., Shanahan, M. et al. · Frontiers in Human Neuroscience (2014)
Carhart-Harris, R. L., Nutt, D. J. · Journal of Psychopharmacology (2017)
Carhart-Harris, R. L., Roseman, L., Haijen, E. C. H. M. et al. · Journal of Psychopharmacology (2018)
Fond, G., Loundou, A., Macgregor, A. et al. · Psychopharmacology (2014)
Show all 33 referencesShow fewer
Griffiths, R. R., Richards, W. A., Mccann, U. et al. · Journal of Psychopharmacology (2006)
Haijen, E. C. H. M., Kaelen, M., Roseman, L. et al. · Frontiers in Pharmacology (2018)
Johnson, M. W., Hendricks, P. S., Barrett, F. S. et al. · Pharmacology and Therapeutics (2019)
Kishimoto, T., Chawla, J. M., Hagi, K. et al. · Psychological Medicine (2016)
Krupitsky, E. M., Grinenko, A. Y. · Journal of Psychoactive Drugs (1997)
Luckenbaugh, D. A., Niciu, M. J., Ionescu, D. F. et al. · Journal of Affective Disorders (2014)
Ly, C., Greb, A. C., Cameron, L. P. et al. · Cell Reports (2018)
Majic, T., Schmidt, T. T., Gallinat, J. · Journal of Clinical Psychopharmacology (2015)
Mathai, D. S., Meyer, M. J., Storch, E. A. et al. · Journal of Affective Disorders (2020)
Nutt, D. J. · Dialogues in Clinical Neuroscience (2019)
Pahnke, W. N. · Psychedelic Review (1969)
Reiff, C. M., Richman, E. E., Nemeroff, C. B. et al. · American Journal of Psychiatry (2020)
Roseman, L., Haijen, E. C. H. M., Idialu-Ikato, K. et al. · Journal of Psychopharmacology (2019)
Roseman, L., Nutt, D. J., Carhart-Harris, R. L. · Frontiers in Pharmacology (2018)
Sanacora, G., Schatzberg, A. F. · Neuropsychopharmacology (2021)
Schenberg, E. E. · Frontiers in Pharmacology (2018)
Sos, P., Klirova, M., Novák, T. et al. · Neuropsychiatric Disease And Treatment (2013)
Studerus, E., Gamma, A., Vollenweider, F. X. · PLOS ONE (2010)
Sumner, R. L., Mcmillan, R., Spriggs, M. J. et al. · European Neuropsychopharmacology (2020)
Vollenweider, F. X., Kometer, M. · Nature Reviews Neuroscience (2010)
Watts, R., Day, C. M., Krzanowski, J. et al. · Journal of Humanistic Psychology (2017)
Watts, R., Luoma, J. B. · Journal of Contextual Behavioral Science (2020)
Wolff, M., Evens, R., Mertens, L. J. et al. · Frontiers in Psychiatry (2020)
Cited By (8)
Papers in Blossom that reference this study
Mallevays, M., Fuet, L., Danon, M. et al. · MedRvix (2026)
Aepfelbacher, J., Panny, B., Price, R. · Biological Psychiatry (2024)
Mathai, D. S., Hilbert, S., Sepeda, N. D. et al. · Psychedelic Medicine (2023)
Hack, L. M., Zhang, X., Heifets, B. D. et al. · Nature Communications (2023)
Batievsky, D., Weiner, M., Kaplan, S. B. et al. · Frontiers in Pain Research (2023)
Mathai, D. S., Nayak, S., Yaden, D. B. et al. · Psychopharmacology (2023)
Breeksema, J. J., Niemeijer, A. R., Kuin, B. et al. · Frontiers in Psychiatry (2022)
Mollaahmetoglu, O. M., Keeler, J., Ashbullby, K. J. et al. · Frontiers in Psychiatry (2021)
Your Personal Research Library
Go Pro to save papers, add notes, rate studies, and organize your research into custom shelves.