Faculty

Richard Zeifman is an Assistant Professor of Psychology (Clinical) and Director of the Psychedelic-Assisted THerapy (PATH) Lab at The New School for Social Research. 

Richard's research focuses on examining the safety, efficacy, and mechanisms of change underlying psychedelic-assisted therapy. He conducts clinical trials, real-world effectiveness studies, and uses multi-method approaches to study, and elucidate the mechanisms underlying, psychedelic-assisted therapy for the treatment of psychiatric disorders. He is a co-investigator on several clinical trials examining psychedelic-assisted therapy for the treatment of major depressive disorder, cancer-related distress, and posttraumatic stress disorder (PTSD).

BA 2015, York University

MA 2017, Toronto Metropolitan University

PhD 2022, Toronto Metropolitan University

Google Scholar Page

Kamaleddin, M. A., Mirjalili, M., Barzegar, R., Le, N. T., Cote, Z., Winkler, O., Burback, L., Zhang, Y., Zaiane, O. R., Monson, C., Sharma, D., Krishnan, S., Greenshaw, A., Zeifman, R., Selby, P., & Bhat, V. (2026). Multi-agent large language model framework for psychotherapy fidelity assessment in motivational interviewing and cognitive behavioral therapy training: A cross-sectional, simulation-based evaluation. JMIR Medical Education, 12, e92964. https://doi.org10.2196/92964

Meshkat, S., Leung, M., Meshkat, S., Lin, Q., Wijendran, D., Reichelt, A. C., Zhang, Y., Burback, L., Winkler, O., Greenshaw, A., Monson, C. M., Vermetten, E., Jetly, R., Lou, W., Zeifman, R. J., & Bhat, V. (2026). Effects of psychedelics microdosing on psychological outcomes in healthy adults: A systematic review & meta-analysis. CNS Drugs. Advance online publication. https://doi.org/10.1007/s40263-026-01325-5

Teferra, B. G., Sidharta, C. K., Hsiang, W., Rueda, A., Guan, B., Zhang, Y., Burback, L., Winkler, O., Greenshaw, A., Vermetten, E., Jetly, R., Sareen, J., Lanius, R., Zeifman, R. J., Sharma, D., Krishnan, S., Monson, C., & Bhat, V. (2026). Zero-shot large language models for prediction of PTSD symptoms from clinical interview transcripts. The Canadian Journal of Psychiatry. Advance online publication. https://doi.org/10.1177/07067437261468

Wolff, M., Kangaslampi, S., Zeifman, R. J., & Spangemacher, M. (2026). Strong alliance, weak conclusions: Comment on Goodwin et al. “The role of therapeutic alliance in psilocybin treatment for treatment-resistant depression.” Psychedelic Medicine. Advance online publication. https://doi.org/10.1177/283144252614610

Lyons, T., Spriggs, M., Kerkelä, L., Rosas, F, E., Roseman, L., Mediano, P. A. M., Timmermann, C., Oesterich, L., Pagni, B., Zeifman, R. J., Hampshire, A., Trender, W., Douglas, H. M., Girn, M., Godfrey, K., Sharif, F., Espasiano, L., Wall, M. B., Erritzoe, D., Nutt, D. J., & Carhart-Harris RL (2026). Human brain changes after first psilocybin use. Nature Communications, 17, 3977. https://doi.org/10.1038/s41467-026-71962-3

Mallard, A. J., Broussard, M., Zeifman, R. J., Cloutier, S., Ross, S., Bogenschutz, M., & Pagni, B. (2026). Psychedelic use and mystical-type experiences are associated with greater self-compassion, compassionate love, and life satisfaction. Journal of Humanistic Psychology. Advance online publication. https://doi.org/10.1177/00221678261442571

Teferra, B. G., Huang, S., Johny, N., Perivolaris, A., Al-Shamali, H., Karisa Parkington, K., Rueda, A., Zeifman, R. J., Sharma, D., Krishnan, S., Monson, C., & Bhat, V. (2026). Alignment of large language model responses with human therapists in motivational interviewing. JAMA Network Open, 9(3), e262750. https://doi.org/10.1001/jamanetworkopen.2026.2750

Meshkat, S., Lin, Q., Sousa-Ho, R., Demchenko, I., Zeifman, R. J., Fang, H., Reichelt, A. C., Zhang, Y., Winklet, O., Greenshaw, A., Monson, C., Vermetten, E., Jetly, R., Lou, W., Husain, M. I., Burke, M., & Bhat, V. (2026). Magnitude of response in treatment and control groups within psychedelic trials for psychiatric disorders: A meta-analysis. European Psychiatry. Advance online publication. https://doi.org/10.1192/j.eurpsy.2026.10168

Mehmood, M. K., Bremler, R., Kettner, H., Roseman, L., Spriggs, M. J., Damgaard, L., Carhart-Harris, R., Erritzoe, D., & Zeifman, R. J. (2025). Ceremonial psychedelic experiences and changes in mental health in those with adverse childhood experiences. Psychedelic Medicine. Advance online publication. https://doi.org/10.1177/28314425251392251

Gordon, A. R., Carrithers, B. M., Pagni, B., Kettner, H., Marrocu, A., Nayak, S., Weiss, B. J., Carhart-Harris, R. L., Roberts, D. E., Erritzoe, D., Garcia-Romeu, A., Jackson, H., Lowe, M. X., & Zeifman, R. J. (2025). The effect of psychedelics on individuals with a personality disorder: Results from two prospective cohort studies. Psychedelic Medicine. Advance online publication. https://doi.org/10.1177/28314425251382930

Agin-Liebes, G., Zeifman, R. J., & Mitchel, J. M. (2025). Self-compassion mediates treatment effects in MDMA-assisted therapy for posttraumatic stress disorder. European Journal of Psychotraumatology, 16(1), 2485513. https://doi.org/10.1080/20008066.2025.2485513

Wagner, A. C., Schlagintweit, H. E., Munroe, M., Buono, S., Antonopoulos, I., Traynor, J. M., Lane, J., Zeifman, R. J., Mithoefer, A. T., Monson, C. M., Mithoefer, M. C., Uy, P., & Bruni, A. (2025). Protocol for a Phase 2 open-label pilot study of MDMA-assisted cognitive processing therapy for posttraumatic stress disorder. The Behavior Therapist, 48(5), 620-635.

Carrithers, B. M., Roberts, D. E., Weiss, B. J., King, J. D., Carhart-Harris, R. L., Gordon, A. R., Pagni, B. A., Moreau, M., Ross, S., & Zeifman, R. J. (2025). Exploring serotonergic psychedelics as a treatment for personality disorders. Neuropharmacology, 272, 110413. https://doi.org/10.1016/j.neuropharm.2025.110413

Zeifman, R. J., Spriggs, M. J., Kettner, H., Lyons, T., Rosas, F., Mediano, P., Erritzoe, D., & Carhart-Harris, R. (2025). From relaxed beliefs under psychedelics (REBUS) to revised beliefs after psychedelics (REBAS). Scientific Reports, 15, 3651. https://doi.org/10.1038/s41598-023-28111-3

Pagni, B. A., Zeifman, R. J., Mennenga, S. E., Carrithers, B., Goldway, N., Bhatt, S., O’Donnell, K. C., Ross, S., & Bogenschutz, M. P. (2025). Multi-dimensional personality changes following psilocybin-assisted therapy in patients with alcohol use disorder: Results from a double-blind, randomized, placebo-controlled trial. American Journal of Psychiatry, 182(1), 114-125. https://doi.org/10.1176/appi.ajp.20230887

Petridis P. D., Grinband, J., Agin-Liebes, G., Kinslow C. J., Zeifman, R. J., Griffiths, R. R., & Ross, S. (2024). Psilocybin-assisted psychotherapy improves psychiatric symptoms across multiple dimensions in patients with cancer. Nature Mental Health, 2, 1408-1414. https://doi.org/10.1038/s44220-024-00331-0

Sloshower, J., Zeifman, R. J., Guss, J., Krause, R., Safi-Aghdam, H., Pathania, S., Pittman, B., & D’Souza, D. C. (2024). Psychological flexibility as a mechanism of change in psilocybin-assisted therapy for major depression: Results from an exploratory placebo-controlled trial. Scientific Reports, 14, 8833. https://doi.org/10.1038/s41598-024-58318-x

Zeifman, R. J., Hernandez, K. M., Song, J., Liebman, R. E., Ip, J., Burdo, J., Johnson, C.,Wiltsey Stirman, S., & Monson, C. M. (2024). Which PTSD clusters and symptoms are central to reducing suicidal ideation? A network and cross-lagged analysis among individuals receiving cognitive processing therapy. European Journal of Psychotraumatology, 15(1), 2434315. https://doi.org/10.1080/20008066.2024.2434315 

Zeifman, R. J., Kettner, H., Ross, S., Weiss, B., Mithoefer, M. C., Mithoefer, A. T., & Wagner, A. C. (2024). Preliminary evidence for the importance of therapeutic alliance in MDMA-assisted psychotherapy for posttraumatic stress disorder. European Journal of Psychotraumatology, 15(1), 2297536. https://doi.org/10.1080/20008066.2023.2297536

Zeifman, R. J., & Maia, L. O. (2024). Methodological concerns in psychedelic research: The issues of nonequivalent psychological support and generalizability. European Neuropsychopharmacology, 78, 13-15. https://doi.org/10.1016/j.euroneuro.2023.09.007 

Zeifman, R. J., Kettner, H., Pagni, B. A., Mallard, A.,* Roberts, D. E., Erritzoe, D., & Carhart-Harris, R., L. (2023). Co-use of MDMA with psilocybin/LSD may buffer against challenging experiences and enhance positive experiences. Scientific Reports, 13, 13645. https://doi.org/10.1038/s41598-023-40856-5

Zeifman, R. J., Dengdeng, Y., Singhal, N., Wang, G., Nayak, S. M., & Weisman, C. R. (2022). Decreases in suicidality following psychedelic therapy: A meta-analysis of individual patient data across clinical trials. The Journal of Clinical Psychiatry, 83(2), 39235. https://doi.org/10.4088/JCP.21r14057

Zeifman, R. J., Landy, M. S. H., Liebman, R., Fitzpatrick, S., & Monson, C. M. (2021). Optimizing treatment for comorbid borderline personality disorder and posttraumatic stress disorder: A systematic review of psychotherapeutic approaches and treatment efficacy. Clinical Psychology Review, 86, 102030. https://doi.org/10.1016/j.cpr.2021.102030

Zeifman, R. J., Singhal, N., Breslow, L., & Weisman, C. R. (2021). On the relationship between classic psychedelics and suicidality: A systematic review. ACS Pharmacology & Translational Science, 4(2), 436-451. https://doi.org/10.1021/acsptsci.1c00024 Zeifman, R. J., Wagner, A. C., Monson, C. M., & Carhart-Harris, R. (2023). How does psilocybin therapy work? An exploration of experiential avoidance as a putative mechanism of change. Journal of Affective Disorders, 334, 100-112. https://doi.org/10.1016/j.jad.2023.04.105