Skip to content

Alexander Belser

Yale University, Department of Psychology, New Haven, CT USA.

8 papers in the library · 2,525 citations · publishing 2016-2023

Papers

Rapid and sustained symptom reduction following psilocybin treatment for anxiety and depression in patients with life-threatening cancer: a randomized controlled trial

Journal of Psychopharmacology November 30, 2016 Stephen Ross, Anthony Bossis, Jeffrey Guss et al. 1,699 citations

A single moderate dose of psilocybin (0.3 mg/kg), combined with psychotherapy, produced immediate and sustained improvements in anxiety and depression among 29 patients with cancer-related psychological distress. At the 6.5-month follow-up, approximately 60–80% of participants continued to show clinically significant reductions in depression or anxiety. Psilocybin also decreased demoralization and hopelessness, improved spiritual wellbeing, quality of life, and attitudes toward death. The therapeutic effects on anxiety and depression were mediated by the psilocybin-induced mystical experience.

Patient Experiences of Psilocybin-Assisted Psychotherapy: An Interpretative Phenomenological Analysis

Journal of Humanistic Psychology April 28, 2017 Alexander Belser, Gabrielle Agin-Liebes, Thomas Cody Swift et al. 305 citations

In psilocybin-assisted psychotherapy for cancer patients with anxiety, participants commonly reported feelings of interconnectedness, emotional range, meaningful visual phenomena, and revised life priorities. Most described exalted joy, bliss, love, and transient distress, while some experienced lasting identity changes, synesthesia, catharsis, improved relationships, and forgiveness. The findings suggest psilocybin-assisted psychotherapy may effectively treat psychological distress in cancer patients.

Cancer at the Dinner Table: Experiences of Psilocybin-Assisted Psychotherapy for the Treatment of Cancer-Related Distress

Journal of Humanistic Psychology June 14, 2017 Thomas Cody Swift, Alexander Belser, Gabrielle Agin-Liebes et al. 187 citations

In psilocybin-assisted psychotherapy for cancer patients with anxiety, participants described reconciling with death, acknowledging cancer's place in life, and emotionally uncoupling from the disease. The immersive and sometimes distressing psilocybin session led to spiritual or religious interpretations, a felt reconnection to life, reclaiming presence, and greater confidence about cancer recurrence. Patients also reported anxiety and trauma related to cancer and a perceived lack of emotional support. The findings suggest psychological mechanisms—such as emotional uncoupling and reconciliation with death—that may underlie large reductions in anxiety and depression observed in recent trials.

Individual Experiences in Four Cancer Patients Following Psilocybin-Assisted Psychotherapy

Frontiers in Pharmacology April 3, 2018 Tara C. Malone, Sarah E. Mennenga, Jeffrey Guss et al. 128 citations

Cancer patients who receive psilocybin-assisted psychotherapy often have personalized experiences that extend beyond their diagnosis, centering on self-compassion, love, acceptance of death, and past trauma. In a double-blind trial, 29 patients with cancer-related anxiety and depression received either psilocybin or niacin with psychotherapy. Psilocybin produced rapid and lasting reductions in anxiety and depression. Detailed accounts of four participants show that while the content of each psilocybin session was unique, common themes emerged. The findings highlight how the subjective effects of psilocybin can address individual spiritual and psychological needs.

Of Roots and Fruits: A Comparison of Psychedelic and Nonpsychedelic Mystical Experiences

Journal of Humanistic Psychology October 24, 2016 David B. Yaden, Khoa D. Le Nguyen, Margaret L. Kern et al. 125 citations

Religious, spiritual, or mystical experiences triggered by psychedelic substances are rated as more intensely mystical and produce a reduced fear of death, a greater sense of purpose, and increased spirituality compared to similar experiences arising through other means. These findings held even after controlling for gender, education, socioeconomic status, and religious affiliation. The results support the view that psychedelic-induced experiences are genuinely mystical and generally positive in outcome.

Posttraumatic Growth After MDMA‐Assisted Psychotherapy for Posttraumatic Stress Disorder

Journal of Traumatic Stress February 19, 2020 Ingmar Gorman, Alexander Belser, Lisa Jerome et al. 43 citations

MDMA-assisted psychotherapy for posttraumatic stress disorder (PTSD) not only reduces symptoms but also promotes posttraumatic growth (PTG)—positive changes in self-perception, relationships, and life philosophy. Pooled data from three phase 2 clinical trials with 60 participants showed that those receiving active MDMA (75–125 mg) had significantly more PTG and larger reductions in PTSD symptom severity at the primary endpoint compared to the control group (0–40 mg MDMA). At 12-month follow-up, PTG remained higher, symptom severity lower, and two-thirds of participants no longer met PTSD criteria. These large-magnitude effects suggest PTG may be a new mechanism of action for this treatment.

Single-dose psilocybin for treatment-resistant obsessive-compulsive disorder: A case report

Heliyon December 1, 2022 Benjamin Kelmendi, Giuliana DePalmer, Gayle Maloney et al. 34 citations

A patient with treatment-resistant obsessive-compulsive disorder received psilocybin and was followed for a year. His OCD symptoms markedly improved, with the YBOCS score dropping from 24 to between 0 and 2. Broader gains included better emotional connection, social and work functioning, and quality of life. This individual was an early participant in an ongoing controlled study. The results are preliminary but suggest that carefully monitored and supported psychedelic treatment may hold therapeutic potential for obsessions and compulsions.

A Systematic Review of Reporting Practices in Psychedelic Clinical Trials: Psychological Support, Therapy, and Psychosocial Interventions

July 18, 2023 Bill Brennan, Alex R. Kelman, Alexander Belser 4 citations preprint

A systematic review of 33 published psychedelic clinical trials found that many reports inadequately describe the psychosocial interventions provided alongside the drugs. Over 80% did not report assessing treatment fidelity, more than half did not mention using a therapy manual, and nearly half omitted the duration or number of therapy sessions. This underreporting, worse than in non-psychedelic trials, undermines research standardization and the ability to understand how these interventions affect outcomes. The authors recommend improved reporting practices to clarify the role of psychological support in psychedelic treatment.