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Stephen Ross

Department of Neurology, University of California San Francisco, San Francisco, California, USA.

30 papers in the library · 4,504 citations · publishing 2012-2026

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.

Percentage of Heavy Drinking Days Following Psilocybin-Assisted Psychotherapy vs Placebo in the Treatment of Adult Patients With Alcohol Use Disorder

JAMA Psychiatry August 24, 2022 Michael P. Bogenschutz, Stephen Ross, Snehal Bhatt et al. 668 citations

Two doses of psilocybin, given alongside psychotherapy, substantially reduced heavy drinking in people with alcohol use disorder compared to an active placebo (diphenhydramine) plus psychotherapy. Over 32 weeks, heavy drinking days averaged 9.7% in the psilocybin group versus 23.6% in the placebo group—a mean difference of 13.9 percentage points. Daily alcohol consumption was also lower with psilocybin. No serious adverse events occurred in the psilocybin group. The findings support further research into psilocybin-assisted treatment for alcohol use disorder.

Single-Dose Psilocybin Treatment for Major Depressive Disorder

JAMA August 31, 2023 Charles L Raison, Gerard Sanacora, Joshua Woolley et al. 493 citations

A single 25-mg dose of synthetic psilocybin, administered with psychological support, produced a clinically significant and sustained reduction in depressive symptoms and functional disability over 43 days in adults with major depressive disorder. In a phase 2 trial of 104 participants, those receiving psilocybin showed a mean 12.3-point greater improvement on the Montgomery-Asberg Depression Rating Scale at day 43 compared with those receiving a niacin placebo. Psilocybin also improved daily functioning and led to more sustained response, though not remission. No serious adverse events occurred, but psilocybin was associated with more overall and severe adverse events.

Long-term follow-up of psilocybin-assisted psychotherapy for psychiatric and existential distress in patients with life-threatening cancer

Journal of Psychopharmacology January 9, 2020 Gabrielle Agin-Liebes, Tara C. Malone, Matthew M. Yalch et al. 353 citations

A long-term follow-up of a randomized trial found that psilocybin-assisted psychotherapy produced lasting reductions in anxiety, depression, hopelessness, demoralization, and death anxiety in people with cancer-related psychiatric distress. At an average of 3.2 and 4.5 years after psilocybin administration, 60–80% of participants still showed clinically significant antidepressant or anxiolytic responses. Most participants (71–100%) attributed positive life changes to the therapy and rated it among the most personally meaningful and spiritually significant experiences of their lives. The study's conclusions are limited by the crossover design of the original trial, but the results suggest psilocybin-assisted therapy may promote long-term relief from cancer-related distress.

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.

Acute and Sustained Reductions in Loss of Meaning and Suicidal Ideation Following Psilocybin-Assisted Psychotherapy for Psychiatric and Existential Distress in Life-Threatening Cancer

ACS Pharmacology & Translational Science March 18, 2021 Stephen Ross, Gabrielle Agin-Liebes, Sharon L. Lo et al. 133 citations

People with advanced cancer face elevated risks of desire for hastened death, suicidal ideation, and completed suicide. Loss of meaning, a component of demoralization, predicts these outcomes. In a randomized controlled trial, psilocybin-assisted psychotherapy produced rapid and sustained improvements in depression, demoralization, and hopelessness. Secondary analyses showed that among participants with elevated suicidal ideation at baseline, reductions in suicidal ideation appeared as early as 8 hours and persisted for 6.5 months. Large reductions in loss of meaning emerged 2 weeks after treatment and remained significant at 6.5 months and at 3.2 and 4.5 year follow-ups. The findings suggest psilocybin-assisted psychotherapy may be an effective antisuicidal intervention for cancer patients due to its positive impact on hopelessness and meaning-making.

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.

Clinical Interpretations of Patient Experience in a Trial of Psilocybin-Assisted Psychotherapy for Alcohol Use Disorder

Frontiers in Pharmacology February 20, 2018 Michael P. Bogenschutz, Samantha K. Podrebarac, Jessie H. Duane et al. 125 citations

After a 40-year pause, clinical research on classic hallucinogens for addiction has resumed. An ongoing double-blind placebo-controlled trial tests psilocybin-assisted treatment for alcohol use disorder, building on a small open-label feasibility study. Descriptive case studies of three participants illustrate treatment trajectories. Pivotal moments during psilocybin sessions are individualized, vivid, and memorable, often extending beyond the clinical problem. Participants experienced lasting shifts in self-perception, consciousness, and relationship with alcohol. Experiences of catharsis, forgiveness, self-compassion, and love were as salient as mystical content. Feelings of increased mindfulness, spaciousness, and control over choices and behavior were reported. The treatment elicits highly variable experiences that appear to meet individual needs.

Therapeutic use of classic psychedelics to treat cancer-related psychiatric distress

International Review of Psychiatry July 4, 2018 Stephen Ross 103 citations

Cancer patients often experience severe psychological and existential distress, which worsens medical outcomes. Early studies from the 1960s-1970s suggested that psychedelic drugs like psilocybin and LSD might help treat this distress. After a long pause, research resumed in the last two decades. A systematic review of clinical trials from 1960-2018 identified 10 eligible trials with 445 participants, most with advanced or terminal cancer. Six open-label trials (1964-1980, n=341) suggested LSD therapy may improve depression, anxiety, and fear of death. Four randomized controlled trials (2011-2016, n=104), mostly using psilocybin (n=92), demonstrated that psychedelic-assisted treatment can produce rapid, robust, and sustained improvements in cancer-related psychological and existential distress.

Serotonergic hallucinogens and emerging targets for addiction pharmacotherapies.

The Psychiatric clinics of North America June 1, 2012 Stephen Ross 54 citations

Serotonergic hallucinogen-assisted psychotherapy may prove safe and effective for treating substance use disorders in controlled trials, offering a novel treatment paradigm. These substances differ from other drugs of abuse by not producing dependence syndromes, with effects on the nucleus accumbens and dopamine ranging from inhibition to slight activation without causing addiction. Risks include adverse psychological events, manageable through careful screening, and low potential for misuse. Their ability to treat addictive, psychiatric, and existential disorders represents a potential paradigmatic shift in psychiatry.

Preliminary evidence for the importance of therapeutic alliance in MDMA-assisted psychotherapy for posttraumatic stress disorder.

European journal of psychotraumatology January 1, 2024 Richard J Zeifman, Hannes Kettner, Stephen Ross et al. 34 citations

Therapeutic alliance—the quality of the relationship between therapist and client—predicts improvement in PTSD symptoms after MDMA-assisted psychotherapy. Among 22 adults with chronic PTSD who received MDMA during a clinical trial, stronger therapeutic alliance measured at sessions 4 and 9 (but not before the third session) was associated with lower clinician-assessed PTSD severity after treatment, even after accounting for initial symptom severity. Self-reported PTSD severity was also predicted by alliance at baseline, session 4, and session 9, though the baseline finding did not survive correction for multiple comparisons. These results provide initial evidence that common psychotherapeutic factors like alliance contribute to outcomes in MDMA-assisted therapy.

Co-use of MDMA with psilocybin/LSD may buffer against challenging experiences and enhance positive experiences

Scientific Reports August 22, 2023 Hannes Kettner, Stephen Ross, Richard J. Zeifman et al. 31 citations

Co-using a low dose of MDMA with psilocybin or LSD is associated with less intense challenging experiences—such as grief and fear—and increased feelings of self-compassion, love, and gratitude, compared to using psilocybin or LSD alone. In a survey of 698 people planning to use these substances, the 27 who also took a low dose of MDMA reported these benefits without a reduction in mystical-type experiences or compassion. Medium-to-high MDMA doses did not show the same effects. The findings suggest MDMA may buffer against some difficult aspects of psychedelic experiences, but the study's small, non-experimental convenience sample limits certainty.

Are psychedelic medicines the reset for chronic pain? Preliminary findings and research needs

Neuropharmacology April 2, 2023 Farah Z Zia, Michael H Baumann, Sean J Belouin et al. 28 citations

Chronic pain is a leading cause of disability and opioid overdose in the United States. While many people manage pain with existing medicines and psychosocial treatments, others find these options ineffective or unacceptable due to side effects and risks. Preliminary evidence suggests psychedelics may improve quality of life, functionality, and reduce disability and distress for people whose pain may never be completely relieved. This commentary calls for more basic research and clinical trials to explore psychedelics' potential in chronic pain management, and to determine whether effects stem from direct antinociceptive or anti-inflammatory mechanisms, or from increased tolerability, acceptance, and spirituality that mediate therapeutic effects seen in psychiatric disorders.

Psilocybin for alcohol use disorder: Rationale and design considerations for a randomized controlled trial.

Contemporary clinical trials December 1, 2022 Kelley C O'Donnell, Sarah E Mennenga, Lindsey T Owens et al. 24 citations

Classic psychedelics like psilocybin may help people change their behavior in substance use disorders. This paper describes the protocol for a multi-site, double-blind, randomized controlled trial that tested psilocybin-assisted psychotherapy in 96 alcohol-dependent volunteers. Participants received either psilocybin or an active placebo (diphenhydramine) during two dosing sessions, alongside a structured 12-week psychotherapy platform. The primary outcome was the proportion of heavy drinking days over 32 weeks after the first dose. Secondary outcomes included safety, abstinence, craving, and self-efficacy. The primary results are reported elsewhere; this paper focuses on the rationale and design decisions.

Multidimensional Personality Changes Following Psilocybin-Assisted Therapy in Patients With Alcohol Use Disorder: Results From a Double-Blind, Placebo-Controlled Clinical Trial

American Journal of Psychiatry January 1, 2025 Noam Goldway, Snehal Bhatt, Stephen Ross et al. 23 citations

Psilocybin-assisted therapy (PAT) produced lasting changes in personality, indicating a normalization of abnormal personality trait expression in people with alcohol use disorder. The findings suggest that PAT may reduce impulsiveness, or that impulsive individuals may inherently respond better to the therapy. Further research is needed to clarify the mechanism.

Older adults in psychedelic-assisted therapy trials: A systematic review

Journal of Psychopharmacology January 1, 2024 Lisa Bouchet, Zachary Sager, Antoine Yrondi et al. 22 citations

Older adults (65+) account for less than 1.4% of participants in psychedelic clinical trials, despite these compounds showing potential for conditions common in this age group, such as depression, anxiety, and existential distress. A systematic review of 36 trials involving 1,400 patients found only 19 were aged 65 or older. Safety data for 10 of these older adults showed no serious adverse events; only transient mild-to-moderate effects like anxiety, gastrointestinal upset, and hypertension occurred during dosing sessions. The authors conclude that psychedelic-assisted psychotherapy appears safe and well tolerated in older adults and warrants more rigorous investigation for psychiatric treatment in this population.

If the Doors of Perception Were Cleansed, Would Chronic Pain be Relieved? Evaluating the Benefits and Risks of Psychedelics.

The journal of pain October 1, 2022 Robert H Dworkin, Brian T Anderson, Nick Andrews et al. 22 citations

Psychedelic substances have been used historically for spiritual and mystical experiences, and recent interest focuses on their potential to treat chronic pain. Clinical trials support psychedelics' effectiveness for psychiatric conditions, but studies on chronic pain—such as cancer pain, phantom limb pain, migraine, and cluster headache—are few and mostly uncontrolled. Risks are relatively rare with careful patient screening and supervision. Key challenges include identifying mechanisms of action, selecting appropriate pain conditions, designing rigorous trials with proper control groups, minimizing unblinding bias, and accounting for patient mindset and setting. Evidence-based recommendations are needed for future research to yield informative results.

Effects of Psilocybin on Religious and Spiritual Attitudes and Behaviors in Clergy from Various Major World Religions

Psychedelic Medicine May 16, 2025 Roland R. Griffiths, William A. Richards, Robert L. Jesse et al. 14 citations

In clergy from various world religions who had never used psychedelics, two supported psilocybin sessions (20 mg/70 kg, then 20 or 30 mg/70 kg) led to sustained positive changes in religious practices, attitudes about their religion, and effectiveness as a religious leader, as well as in non-religious attitudes, moods, and behavior, compared with a waitlist control group. At 16‑month follow‑up, 96% rated at least one experience among the top five most spiritually significant of their lives, 42% rated it the single most profound, and 79% reported positive effects on daily sense of the sacred. No serious adverse events occurred, though 46% rated an experience among the top five most psychologically challenging of their lives.

MDMA-Assisted Psychotherapy for Borderline Personality Disorder.

Focus (American Psychiatric Publishing) October 1, 2022 Jenna M Traynor, Daniel E Roberts, Stephen Ross et al. 14 citations

Borderline personality disorder is a complex psychiatric condition with limited and often ineffective treatment options, high variability in patient response, and frequent dropout from therapy. This review considers the potential of MDMA-assisted psychotherapy (MDMA-AP) as a new or complementary treatment. Based on MDMA-AP's promise in treating overlapping disorders like posttraumatic stress disorder, the authors propose initial treatment targets and hypothesized mechanisms of change grounded in prior literature and theory. They also outline considerations for designing clinical trials to investigate the safety, feasibility, and preliminary effects of MDMA-AP for borderline personality disorder.

Psilocybin-assisted psychotherapy for existential distress: practical considerations for therapeutic application—a review

Annals of Palliative Medicine August 22, 2024 Arum Kim, Barley Halton, Akash Shah et al. 11 citations

Existential distress, a distinct condition from depression or anxiety, is common among patients with life-threatening illnesses and is linked to worse quality of life, suicidal ideation, and requests for hastened death. Traditional medications and psychotherapy show limited effectiveness for this condition. Psychedelic drugs, such as psilocybin and LSD, combined with psychotherapy, have produced rapid and sustained reductions in existential and psychiatric distress, offering a promising treatment for palliative care patients. This narrative review covers the history of psychedelic medicine, including early studies and modern clinical trials, and outlines practical considerations for psilocybin-assisted therapy, such as pharmacokinetics, patient selection, dosing, protocol design, and safety measures. The review aims to help palliative care providers become familiar with the current science and potential of this treatment.

A Field-Wide Review and Analysis of Study Materials Used in Psilocybin Trials: Assessment of Two Decades of Research

Psychedelic Medicine January 20, 2025 Marianna Graziosi, Gabrielle Agin-Liebes, Mary P Cosimano et al. 9 citations

Psilocybin and other serotonergic psychedelics are used in research settings with safety measures including controlled environments, staff presence, screening, and psychoeducation. An analysis of study materials from psilocybin trials over the past two decades found that psychoeducation documents varied but commonly emphasized biological and physical safety, psychological safety and well-being, aspects of setting, and the potential for expectancies. The materials prioritized biological and psychological safety across all sites. The authors also identified elements unrelated to safety that may contribute to participant expectancies and suggest these extrapharmacological factors be studied systematically to maximize safety while minimizing extraneous expectancies.

Exploring the Potential Utility of Psychedelic Therapy for Patients With Amyotrophic Lateral Sclerosis.

Journal of palliative medicine October 1, 2023 Noah D Gold, Austin J Mallard, Jacob C Hermann et al. 5 citations

Psychedelic-assisted psychotherapy (PAP) may help alleviate psychiatric and existential distress in people with amyotrophic lateral sclerosis (ALS), a terminal neurodegenerative disease with an average survival of 3-4 years. The authors suggest PAP could also intervene on neuropathological dimensions of ALS, based on neuroprotective properties of psychedelics and robust improvements seen in other populations. They call for future preclinical trials in ALS models and rigorous clinical trials, given the lack of effective treatments for both disease progression and psychological distress.

Exploring serotonergic psychedelics as a treatment for personality disorders.

Neuropharmacology July 1, 2025 Brennan M Carrithers, Daniel E Roberts, Brandon M Weiss et al. 4 citations

Psychedelic therapy may hold potential for treating personality disorders by promoting adaptive changes in personality, though rigorous research is lacking. This review first examines research on psychedelics in individuals with personality disorders using the DSM-5-TR categorical model, then applies the dimensional DSM-AMPD framework to explore how psychedelics might affect self-functioning, interpersonal functioning, and pathological personality traits. The authors discuss clinical relevance, safety considerations, gaps, and recommendations for treating these complex populations.