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Alan K. Davis

1 Center for Psychedelic and Consciousness Research, Department of Psychiatry and Behavioral Sciences, Johns Hopkins School of Medicine, Baltimore, MD, USA

43 papers in the library · 3,724 citations · publishing 2018-2026

Papers

Naturalistic psychedelic experiences and gender-based self-acceptance in transgender and gender-expansive people

International Journal of Transgender Health March 19, 2025 Skylar J. Gaughan, Angie R. Wootton, Daphne Krantz et al. 6 citations

Transgender and gender-expansive (TGE) people use psychedelics in naturalistic, non-clinical settings to explore and affirm their gender identity. Interviews with 20 TGE individuals revealed three main themes: the mindset and physical setting of a psychedelic experience shape its quality; such experiences often increase self-acceptance of gender identity through greater self-compassion and a broader concept of gender; and participants reported both challenging effects like gender dysphoria and benefits like gender euphoria. The findings suggest clinicians should help TGE clients prepare a gender-affirming setting before psychedelic use and support shifts in gender understanding afterward.

Psychedelic research at a crossroads

Science September 19, 2024 Stacey B. Armstrong, Alan K. Davis 6 citations

Psychedelic-assisted therapy (PAT) combines hallucinogenic drugs like psilocybin and MDMA with psychotherapy, showing potential for treating mental health conditions that affect one in eight people worldwide. Clinical trials in the US and Europe suggest PAT may offer shorter treatment times and stronger effects than existing therapies. However, the field faces significant controversy due to unanswered questions about safety and effectiveness, highlighted by the FDA's recent decision against approving MDMA therapy for PTSD and the retraction of several MDMA trial papers due to unethical therapist conduct and data integrity issues. The research community must address these obstacles to transition from exploratory trials to established, evidence-based treatments.

Psilocybin use patterns and perception of risk among a cohort of Black individuals with Opioid Use Disorder

Journal of Psychedelic Studies August 5, 2022 John Clifton, Annabelle M. Belcher, Aaron D. Greenblatt et al. 6 citations

Among Black individuals diagnosed with Opioid Use Disorder recruited from an urban methadone program, most had heard of psilocybin mushrooms but only 17.8% had ever used them. Over 80% perceived a risk or were unsure of the risk for most psilocybin-related items. About half were willing to try therapy incorporating psilocybin, and half said they would be more likely to try it if FDA-approved for OUD. Most preferred to stay on methadone alone; only one participant chose psilocybin treatment without methadone. The authors suggest culturally informed treatment models and outreach to increase minority representation in psilocybin research.

Increases in Aesthetic Experience Following Ayahuasca Use: A Prospective, Naturalistic Study

Journal of Humanistic Psychology February 27, 2024 Jacob S. Aday, Emily K. Bloesch, Alan K. Davis et al. 5 citations

People who attended an ayahuasca retreat showed increased appreciation of art and beauty one week and one month later, according to a survey of 54 participants. Contrary to expectations, intense drug effects such as mystical experiences, awe, or ego dissolution did not predict these changes. The open-label design limits certainty, but the findings align with anecdotal reports of lasting shifts in aesthetic attitudes after psychedelic use. Further research is needed to identify the mechanisms behind these changes.

Five-year outcomes of psilocybin-assisted therapy for Major Depressive Disorder

Journal of Psychedelic Studies September 4, 2025 Alan K. Davis, Meghan DellaCrosse, Nathan D. Sepeda et al. 4 citations

Over a five-year follow-up period, psilocybin-assisted therapy produced significant and sustained reductions in depression for people with major depressive disorder. Among the 18 participants who completed the study, 67% remained in remission for at least five years after treatment. Anxiety and functional impairment also improved. Qualitative interviews revealed lasting positive changes in mindset, emotional health, and relationships, including enhanced empathy, self-acceptance, and improved interpersonal relationships. No severe adverse events were reported. These findings support the long-term efficacy and safety of psilocybin-assisted therapy for reducing depressive symptoms and improving mental health.

The Epidemiology of Psychedelic Use Among United States Military Veterans

Journal of Psychoactive Drugs September 12, 2024 Katinka Hooyer, Rachel Yehuda, Alan K. Davis et al. 4 citations

About half of U.S. military veterans surveyed reported using psychedelics, most often for healing or treatment (70%) and spiritual purposes (48%). The vast majority (85%) said they benefited from use. Veterans who used psychedelics indicated they would be more likely to use VA services, and they expressed greater interest in psychedelic therapy compared to non-users. However, some adverse outcomes were reported, suggesting that without proper preparation and support, psychedelics may carry risks. The findings point to a potential role for psychedelic-assisted approaches in veteran mental health care.

Seeing the forest for the trees: An ecological systems theory approach to addressing emergent issues in psychedelic-assisted therapy research

Journal of Psychedelic Studies June 5, 2024 Meghan DellaCrosse, A. Garcia-Romeu, Alan K. Davis 4 citations

A lack of consensus and theoretical clarity in psychedelic-assisted therapy research has led to polarized debates and unusual regulatory recommendations, such as removing psychological and medical safety measures to better study drug effects. This commentary argues that an ecological systems theory approach, adapted from Bronfenbrenner, can make contextual and practical factors explicit and testable in research. The proposed conceptual model aims to improve measurement of acute subjective experience and address limitations in current approaches. The authors suggest this framework could help reconcile conflicting perspectives and enhance safety in ongoing clinical trials.

Translation and Initial Psychometric Evaluation of Spanish Versions of Three Psychedelic Acute Effects Measures: Mystical, Challenging, and Insight Experiences

Journal of Psychoactive Drugs July 14, 2023 Christopher Timmermann, Aki Nikolaidis, Alan K. Davis et al. 4 citations

Spanish translations of three questionnaires measuring acute psychedelic effects—the Psychological Insight Questionnaire (PIQ), Challenging Experiences Questionnaire (CEQ), and Mystical Experiences Questionnaire (MEQ)—showed good psychometric properties in a sample of 442 native Spanish speakers. Confirmatory factor analysis confirmed that the factor structures matched the original English versions, and this consistency held across subgroups who had used LSD or psilocybin. Construct validity was supported by positive associations between the PIQ and MEQ and between these measures and changes in cognitive fusion, alongside negative associations with changes in prosocial behaviors. Predictive validity was indicated by strong relationships between persisting effects and scores on the MEQ and PIQ. The Spanish versions can be reliably used in research with Spanish-speaking populations.

Increases in aesthetic experience following ayahuasca use: An open-label, naturalistic study

May 15, 2023 Jacob S. Aday, Emily K. Bloesch, Alan K. Davis et al. 3 citations preprint

People who attended an ayahuasca retreat showed increased engagement with aesthetic experiences—such as appreciation of art, nature, and beauty—one week and one month afterward, compared to before the retreat. The study followed 54 participants and measured aesthetic experience using a validated questionnaire. Although participants reported strong mystical-type experiences, awe, and ego dissolution during their ayahuasca sessions, none of these acute effects predicted the long-term increase in aesthetic engagement. The open-label design limits certainty, but the findings support anecdotal reports that psychedelics can enhance aesthetic appreciation and point to a new area for future research.

Effects of ayahuasca on gratitude and relationships with nature: An open-label, naturalistic study

June 7, 2023 Jacob S. Aday, Emily K. Bloesch, Alan K. Davis et al. 1 citation preprint

People who attended an ayahuasca retreat showed increased gratitude, nature relatedness, and nature appreciation one week and one month afterward, compared with before the retreat. Mystical-type experiences and feelings of awe during the retreat were weakly to moderately linked to these increases, while ego dissolution was not. The findings suggest that the mystical and awe-inducing aspects of ayahuasca may lead to personality changes that benefit mental health and prosocial attitudes, though more research is needed to confirm the results.

Baseline Resilience as a Predictor of Ayahuasca Acute Effects and Moderator of the Relationship between Acute Effects and Psychospiritual Outcomes

Psychedelic Medicine May 9, 2026 Yitong Xin, Alan K. Davis, Susan Yoon et al.

People with higher psychological resilience before an ayahuasca retreat reported more intense acute challenging experiences, such as nausea or emotional distress. Resilience also moderated how those challenging experiences related to later meaning-making: among participants with higher baseline resilience, the link between acute difficulty and a subsequent search for meaning in life was stronger. The findings suggest that resilience may help individuals transform difficult psychedelic moments into psychospiritual growth, pointing to the value of incorporating resilience-building into retreat preparation and integration programs.

5-MeO-DMT Use in Humans: A Scoping Review of Peer-Reviewed Research

January 8, 2026 Michael Esposito, Ana M Ortiz Bernal, Alan K. Davis et al. preprint

A scoping review of 33 peer-reviewed studies on 5-MeO-DMT use in humans found that most interventional studies (13 of 15) used inhalation administration, though dosages and dosing regimens varied widely. Common outcomes measured include cognition, depression, post-traumatic stress disorder, and anxiety. The review highlights large heterogeneity in study design, dosing, and support, and suggests future research should explore different routes of administration and include more neuroimaging, qualitative, and longitudinal data.

Qualitative insights into psilocybin and LSD experiences: Enhanced connection and emotion processing reported by Spanish-speaking survey respondents

Psychedelics November 15, 2025 Meghan DellaCrosse, Shoval Gilead, Rafael Lancelotta et al.

Spanish-speaking individuals who had a memorable psilocybin or LSD experience reported two main themes: deep connection (to nature, others, the present moment, and the substance) and emotion-related experiences (from joy and peace to emotional processing, catharsis, and challenging experiences). The findings are based on a secondary qualitative analysis of open-ended survey responses from 379 Spanish-speaking participants. Similarities appeared across both substances, with some unique nuances. The work underscores the need for diverse populations in psychedelic research to improve generalizability and cultural relevance, and highlights the therapeutic potential of psychedelics while calling for culturally sensitive tools.

Preliminary safety and effectiveness of psilocybin-assisted therapy in adults with fibromyalgia: An open-label, pilot clinical trial

November 4, 2024 Jacob S. Aday, Jenna McAfee, Deirdre A. Conroy et al. preprint

In a small open-label proof-of-concept trial, five adults with fibromyalgia received two doses of psilocybin (15 mg and 25 mg) two weeks apart, along with psychotherapy sessions. No serious adverse events occurred; transient blood pressure or heart rate elevations during dosing resolved by the end of treatment, and four of five participants had temporary headaches. One month after the second dose, participants reported clinically meaningful improvements in pain severity, pain interference, and sleep disturbance. One participant rated their symptoms as very much improved, two as much improved, and two as minimally improved. Improvements were also seen in fibromyalgia symptoms, anxiety, and fatigue. The findings suggest psilocybin-assisted therapy is well-tolerated and warrants larger randomized controlled trials.

Personal and social connection to psychedelics is associated with lower drug use stigma among psychiatrists in the United States

Journal of Psychedelic Studies September 17, 2024 Adam W. Levin, Aryan Sarparast, Paul B Nagib et al.

Among a sample of 180 American psychiatrists (mean age 48.4, 65.5% male, 24.1% trainees), about one-third (32.8%) reported personal use of and social connection to psychedelics. Psychiatrists with such personal connection tended to be younger and have fewer years of practice. Those with personal and social connection were more likely to disagree that using illegal drugs is morally wrong, that users should go to prison, are weak-minded, have no future, are poorly educated, are dishonest, or make them angry. Personal and social proximity to psychedelics is associated with less stigma toward drug use and people who use drugs.

Use of Psilocybin for Improving Health-Related Outcomes and Mental State in Patients with Major Depressive Disorder: Protocol for a Living Systematic Review and Meta-Analysis (Preprint)

August 22, 2022 John M. Pederson, Kathryn Cowie, Averi Barrett et al.

A living systematic review and individual patient data meta-analysis is planned to assess the efficacy and safety of psilocybin for major depressive disorder (MDD). The review will include randomized and non-randomized trials, searching major databases and trial registries, and will analyze primary outcomes of depression severity using validated scales, with secondary outcomes including anxiety, hopelessness, quality of life, and death acceptance. Hierarchical mixed-effects models will account for clustering across studies and examine moderators like age, sex, baseline severity, prior psilocybin use, and dose. The review will be updated continuously as new evidence emerges to inform clinical practice and policy.