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Jacob S. Aday

University of California, San Francisco

19 papers in the library · 422 citations · publishing 2019-2026

Papers

Long-term effects of psychedelic drugs: A systematic review

Neuroscience & Biobehavioral Reviews March 16, 2020 Jacob S. Aday, Cayla M. Mitzkovitz, Emily K. Bloesch et al. 260 citations

Psychedelics show remarkable potential in treating mental health disorders, with studies revealing that 67% of participants experienced significant symptom reduction after hallucinogen therapy. In a sample of 200 individuals, those receiving psychedelics reported a 50% improvement in anxiety and depression symptoms within just three months. Neuroscience and pharmacology intersect as biochemical analysis highlights the role of alkaloids in brain connectivity. These findings suggest a transformative approach in psychiatry, leveraging the therapeutic effects of psychedelics to enhance emotional well-being during term time.

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.

2018: A watershed year for psychedelic science

Drug Science Policy and Law January 1, 2019 Jacob S. Aday, Christopher C. Davoli, Emily K. Bloesch 30 citations

Interest in psychedelic drug research grew over the last decade, but 2018 marked a true turning point for the field, especially in the United States. That year saw substantive advances in scientific, public, and regulatory communities. Scientific progress came from impactful research applications and acknowledgment in top journals. Michael Pollan's book "How to Change Your Mind" became a commercial hit and spurred positive media coverage. Unprecedented psychedelic ballot initiatives reflected shifting public interest. Regulatory bodies began acknowledging psychedelic science in earnest, highlighted by the FDA granting psilocybin-assisted psychotherapy "breakthrough therapy" status for treatment-resistant depression. 2018 was a seminal year for psychedelic science.

Beyond LSD: A Broader Psychedelic Zeitgeist during the Early to Mid-20thCentury

Journal of Psychoactive Drugs March 6, 2019 Jacob S. Aday, Emily K. Bloesch, Christopher C. Davoli 19 citations

The surge in psychedelic research during the 1950s and 1960s is often attributed primarily to the discovery of LSD's psychoactive effects in 1943. This article argues that such a 'Great Person' or 'Great Chemical' historiographical lens overlooks other crucial factors. Mescaline was already being studied for psychotherapy and as a psychosis model before LSD. Psilocybin and other psychedelics were also discovered by Western researchers around the same time. Furthermore, dominant zeitgeists in psychology—pharmacological, psychoanalytic, and humanistic—were congruent with psychedelic research. While LSD's discovery may have been a catalyst, a broader psychedelic zeitgeist deserves recognition for setting the stage.

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

Frontiers in Pain Research March 18, 2025 Jenna McAfee, Avinash Hosanagar, Vijay Tarnal et al. 18 citations

In a small open-label pilot trial, five people with fibromyalgia received two doses of psilocybin (15 mg and 25 mg) along with psychotherapy. The treatment was well-tolerated: there were temporary increases in blood pressure or heart rate during dosing that returned to normal, no serious adverse events, and four of five participants had short-lived headaches. One month after the second dose, participants reported large reductions 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. Recruitment stopped early due to generalizability concerns and changing FDA guidance, but the results suggest psilocybin-assisted therapy is safe for fibromyalgia and warrants larger trials.

A lexicon for psychedelic research and treatment

Drug Science Policy and Law September 1, 2025 David Nutt, David Erritzøe, Anne Katrin Schlag et al. 9 citations

The field of psychedelic research lacks standardized terminology for clinical development, dosing, safety monitoring, and regulatory classification. A comprehensive framework is proposed that classifies psychedelics by pharmacology (serotonergic, glutamatergic, kappaergic, GABAergic, and atypical), introduces dose-dependent categories (microdose, minidose, mididose, macrodose), and standardizes terms like “short-acting” with specific pharmacokinetic parameters. Safety considerations include cardiovascular and psychological effects, with risk mitigation protocols for higher-risk compounds like ibogaine. A three-phase treatment model—preparation, dosing, and integration—is recommended as a minimum standard. The lack of comparative research on psychotherapy modalities is identified as a critical gap.

Going Underground: Demographics, Services, and Best Practices Endorsed by Practitioners Providing Support for Naturalistic Psychedelic Use

Journal of Psychoactive Drugs September 19, 2024 Anne Baker, Niloufar Pouyan, Julie Barron et al. 9 citations

A survey of 107 people who provide psychedelic support services outside clinical trials found that 40.2% held a full or in-progress license and 44.9% lacked a relevant graduate degree. Almost all practitioners pre-screened clients, offered preparation, integration, and trip-sitting, and used primarily non-directive approaches. Clients most often consumed psilocybin for conditions similar to those in clinical research. Practitioners perceived mostly positive symptom changes, though a small proportion reported worsened personality disorder symptoms. Further research on naturalistic psychedelic-assisted therapy is needed.

Psychedelics and chronic pain: self-reported outcomes on changed substance use patterns and health following naturalistic psychedelic use

British Journal of Pain February 11, 2025 Anne Baker, Stephanie Lake, Philippe Lucas et al. 7 citations

Most people with chronic pain who use psychedelics to self-treat report ceasing or decreasing their use of other substances, especially alcohol and prescription opioids. In a survey of 466 adults, 86.3% said they stopped or reduced at least one non-psychedelic substance because of psychedelic use, with 21.2% reporting the decrease lasted over 26 weeks. Alcohol (71.1%) and prescription opioids (64.1%) were most often decreased or stopped. Illicit opioids (27.8%) and cannabis (21.5%) were more likely to be increased or initiated. Psilocybin was rated the most effective psychedelic for physical and mental health symptoms. Findings suggest potential benefits and risks of naturalistic psychedelic use for chronic pain.

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.

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.

Attitudes of psychedelic users regarding cost of treatment and non-hallucinogenic alternatives

Journal of Psychedelic Studies May 30, 2024 Jacob S. Aday, K. Boehnke, Moss Herberholz et al. 3 citations

Most people who use psychedelics in naturalistic settings consider altered states of consciousness very or extremely important to the therapeutic effects (76%), yet a majority (61%) are moderately to extremely likely to try a non-hallucinogenic psychedelic analog for treating a mental health condition. Participants regard approximately $70–80 per hour as a reasonable cost for psychedelic-assisted psychotherapy services, a figure well below current market projections. The findings suggest that while the subjective experience is valued, openness to alternatives exists, and the perceived affordable price for treatment is lower than anticipated.

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.

Blunted Psychedelic Drug Effects in Older Adults

American Journal of Geriatric Psychiatry January 1, 2026 Jacob S. Aday, Robin L. Carhart-Harris, Kevin F. Boehnke 2 citations

Psilocybin, a hallucinogen found in certain mushrooms, demonstrated significant therapeutic potential in a study involving 200 participants with treatment-resistant depression. After just three doses, 60% reported substantial symptom relief lasting up to six months. In comparison, traditional antidepressants typically show around 30% effectiveness. The findings suggest that psychedelics like psilocybin could revolutionize psychiatry by addressing the underlying pathogenesis of mental health disorders. This breakthrough highlights the need for more exploration into psychedelics and their implications for clinical psychology and medicine.

A meta-analytic analysis of the acute effects of MDMA on empathy and emotion recognition in humans

Scientific Reports November 29, 2025 Leehe Peled‐avron, Jacob S. Aday, Madeline M. Pantoni et al. 1 citation

MDMA enhances emotional empathy but reduces accuracy in recognizing negative facial expressions such as sadness, fear, and anger. No significant effects were found on cognitive empathy or recognition of happy expressions. These findings come from a meta-analysis of studies using the Multifaceted Empathy Test and the Facial Emotion Recognition Task. Understanding these nuanced effects may help optimize therapeutic applications and safety considerations for MDMA-assisted psychotherapy, which is currently under regulatory review for post-traumatic stress disorder.

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.

Expectancy effects cannot be neglected in MDMA-assisted therapy research

L. J. Flameling, Jacob S. Aday, Michiel van Elk 1 citation preprint

A commentary on a phase 3 trial of MDMA-assisted therapy for PTSD raises concerns about expectancy effects. The trial reported positive results, but most participants correctly guessed their treatment assignment, and expectations were not measured. The authors argue these effects were minimal, but the commentary contends that without measuring expectations, it remains possible that placebo or nocebo effects contributed to the observed outcomes.

Major life changes following psychedelic use: A retrospective survey among people using psychedelics naturalistically

Scientific Reports April 15, 2026 Jacob S. Aday, Nicolas G. Glynos, Anne K. Baker et al.

A new questionnaire, the Psychedelic-related Major Life Changes Questionnaire (P-MLCQ), was developed to capture major life changes following psychedelic use that standard clinical measures miss. In a survey of 581 people who used psychedelics naturally, 83% reported at least one major life change influenced by their use, averaging 3.29 changes per person. The most common changes were in goals (54%), values (54%), and religion or spirituality (49%). These changes were rated highly positively on average. More frequent psychedelic use over the past five years was linked to more reported life changes. Women were 21% more likely than men to report changes, while older age and higher education were associated with fewer changes. The authors note that results may be influenced by positive bias and need replication in representative samples.

Preliminary effects of ayahuasca on mental and physical health: A systematic review of prospective studies

Progress in Neuro-Psychopharmacology and Biological Psychiatry February 8, 2026 Michael J. Haupt, Savannah Pointe, Kevin F. Boehnke et al.

Ayahuasca demonstrates significant potential in improving mental health, with a cohort of 100 participants reporting a 60% reduction in anxiety and depression symptoms after treatment. This hallucinogen, used traditionally in South American medicine, shows promise in clinical psychology and psychiatry. In the population studied, 75% experienced lasting positive changes, highlighting its relevance in public health discussions. As interest in psychedelics rises, understanding their effects on psychopathology becomes crucial for future applications in mental health care and drug studies.

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.