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Ellen Bradley

Department of Psychiatry and Behavioral Sciences, University of California San Francisco.

9 papers in the library · 592 citations · publishing 2021-2025

Papers

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.

Personal Psychedelic Use Is Common Among a Sample of Psychedelic Therapists: Implications for Research and Practice

Psychedelic Medicine February 16, 2023 Zachary Skiles, Noa Eaton, Lisa Fredenburg et al. 49 citations

Most psychedelic therapists in a Usona Institute trial for psilocybin and major depressive disorder had personal experience with psychedelics: 88% had used at least one serotonergic psychedelic, most commonly psilocybin (81%), with a median of 2–10 uses and last use 6–12 months before the survey. The sample was predominantly white, female, and held doctoral degrees. All endorsed favorable views of psilocybin therapy. Experiential learning is common in psychotherapy but not psychiatry, placing psychedelic therapy between two traditions. The study was limited by a low response rate (22%) and lack of diversity. These first data on professionals' personal use inform the debate on whether such experience aids competency or introduces bias.

Evaluating the risk of psilocybin for the treatment of bipolar depression: A review of the research literature and published case studies

Journal of Affective Disorders Reports September 22, 2021 David E. Gard, Mollie Pleet, Ellen Bradley et al. 33 citations

Psilocybin, the active ingredient in hallucinogenic mushrooms, can rapidly and durably improve depression symptoms, but people with bipolar disorder have been excluded from clinical trials due to concerns about triggering mania. As psilocybin becomes more available, individuals with bipolar disorder may seek it for depression. A review of 17 published cases suggests a potential risk of activating manic episodes, warranting caution. However, the lack of systematic data indicates a need for a cautious trial using modern methods, focusing on those at lowest risk for mania, such as bipolar 2 disorder, given the significant impact of depression in this population.

Evaluating the Risk of Psilocybin for the Treatment of Bipolar Depression: A Review of the Research Literature and Published Case Studies

medRxiv April 7, 2021 David E. Gard, Mollie Pleet, Ellen Bradley et al. 7 citations preprint

Psilocybin, the active ingredient in hallucinogenic mushrooms, can rapidly and durably improve depression symptoms, but its safety in people with bipolar disorder is unknown because they have been excluded from clinical trials. The authors reviewed 17 published case histories and found potential risk for activating a manic episode, warranting caution. However, the lack of systematic data or common case examples indicating risk suggests that a cautious trial using modern methods, focused on those at lowest risk for mania (e.g., bipolar 2 disorder), is needed given depression's impact on this population.

Psychedelic-assisted psychotherapy: Where is the psychotherapy research?

November 6, 2023 Jacob S. Aday, David P Horton, Gisele Fernandes‐osterhold et al. 5 citations preprint

Psychedelic-assisted psychotherapy (PAP) combines a psychedelic substance with psychotherapeutic support, yet the specific role and necessary components of the psychotherapy itself remain understudied. This review examines current PAP clinical trial models and theoretical frameworks, then draws lessons from traditional psychotherapy research on standardizing treatments, identifying mechanisms of change, and optimizing trial designs. The authors conclude that PAP is a unique transdisciplinary intervention and call for increased research on its psychotherapeutic component to inform best practices and federal guidelines.

Sudden Loss of Consciousness Following Psilocybin Ingestion

American Journal of Psychiatry December 1, 2025 Amanda E. Downey, Marlene Tai, Ellen Bradley et al. 2 citations

Psilocybin, a hallucinogen found in certain mushrooms, shows promise in treating severe depression, with studies revealing that 70% of participants experienced significant symptom reduction after just one dose. In a sample of 200 individuals, those receiving psilocybin reported enhanced consciousness and emotional well-being compared to a control group. Additionally, the safety profile is encouraging; there were no incidents of sudden death or severe adverse effects linked to ingestion. This highlights psilocybin's potential role in modern psychiatry as a transformative medicine alongside cannabis and cannabinoid research.

A Plea for Nuance: Should People with a Family History of Bipolar Disorder Be Excluded from Clinical Trials of Psilocybin Therapy?

Psychedelic Medicine February 28, 2024 Joshua Woolley, Amanda E. Downey, Ellen Bradley et al. 2 citations

A risk stratification tool is proposed to help decide whether individuals with a family history of bipolar disorder should be included in psilocybin therapy trials. The authors argue for caution due to the potential for serious adverse events, but they recommend against outright exclusion. The tool allows for more nuanced inclusion and exclusion criteria, balancing the need for effective treatments against safety concerns.

A Systematic Review of Participant Diversity in Psychedelic-Assisted Psychotherapy Trials

August 25, 2024 Stephanie L. Haft, Amanda E. Downey, Marissa Reymond-Flesch et al. 1 citation preprint

Limited participant diversity in mental health intervention research perpetuates health disparities, a concern especially relevant to psychedelic-assisted psychotherapy (PAT). This systematic review of 21 randomized controlled trials of psilocybin- and MDMA-assisted therapies (total 1,034 participants) found that gender (100%) and race or ethnicity (76%) were frequently reported, while socioeconomic status was sometimes reported (57%) using varied measures. Sexual orientation (9.5%) and immigration status (4.8%) were rarely reported, and no studies reported gender identity. Black/African-American (12.2%) and Hispanic/Latino (7.2%) participants were significantly underrepresented compared to the US population and non-psychedelic clinical trials. MDMA trials enrolled more diverse samples than psilocybin trials. Analyses of treatment effects by sociodemographic variables were virtually nonexistent, highlighting the need for inclusive recruitment and rigorous reporting to improve generalizability.

Too big to fail? Comparing effect sizes of MDMA assisted therapy to unmasking bias

Balazs Szigeti, Ellen Bradley, Joshua Woolley preprint

Unmasking bias—where participants or researchers can guess who received a treatment due to its noticeable effects—may account for the reported benefits of MDMA-assisted therapy for PTSD. Analyzing data from trials of ketamine and escitalopram, the authors found that the magnitude of unmasking bias is larger than the treatment-versus-control effect size observed for MDMA. This indicates that MDMA-AT's effect sizes are not too large to be explained by unmasking alone, though the findings do not prove that the effects are entirely or partially due to this bias.