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Zach Walsh

17 papers in the library · 1,039 citations · publishing 2016-2025

Papers

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Daily self-assessment within a regimen of microdosing indicates enhanced psychological functioning on microdosing days relative to non-microdosing days.

Psychopharmacology October 11, 2025 Michelle St Pierre, Elena Argento, Jordyn Cates et al.

Repeated self-administration of small doses of psychedelics, known as microdosing, has been associated with perceived improvements in psychological functioning. However, few studies have examined effects at the daily level. Drawing on data from a naturalistic, prospective, international survey of adults who microdose (N = 1435), we assessed self-reported within-person changes between...

Retraction Note: MDMA-assisted psychotherapy for treatment of PTSD: study design and rationale for phase 3 trials based on pooled analysis of six phase 2 randomized controlled trials.

Psychopharmacology (Berl) November 1, 2024 Michael C Mithoefer, Allison A. Feduccia, Lisa Jerome et al. 9 citations

Retraction Note: MDMA-assisted psychotherapy for treatment of PTSD: study design and rationale for phase 3 trials based on pooled analysis of six phase 2 randomized controlled trials.

Patients' Experiences Discussing Psychedelics for Therapeutic Purposes with Physicians and Other Health Care Providers.

Psychedelic medicine (New Rochelle, N.Y.) September 1, 2024 Michelle St Pierre, Lucas Standing, Yarissa Herman et al. 3 citations

A core component in the provision and receipt of appropriate medical care is trust and communication between patients and physicians. The use of psychedelics for therapeutic purposes (PTPs) has experienced growing attention in the past decade and may be an increasing topic of patient-physician interactions. The stigmatization of psychedelic use may complicate this process. However, patient...

"This is you teaching you:" Exploring providers' perspectives on experiential learning and enhancing patient safety and outcomes in ketamine-assisted therapy.

PLoS One 2024 Elena Argento, Tashia Petker, Jayesh Vig et al. 3 citations

This study explores therapists' perspectives on experiential learning, competencies, and training in ketamine-assisted therapy (KAT), a form of psychedelic-assisted therapy (PAT). We aim to understand how therapists' personal psychedelic experiences influence their self-perceived competency and therapeutic relationships regarding KAT. Licensed therapists from Numinus Wellness clinics in Canada...

Therapeutic Potential of Psilocybin for Treating Psychological Distress among Survivors of Adverse Childhood Experiences: Evidence on Acceptability and Potential Efficacy of Psilocybin Use

Journal of Psychoactive Drugs October 10, 2023 Ashmita Grewal, Kalysha Closson, Gina Martin et al. 11 citations

Survivors of adverse childhood experience are at elevated risk for psychological distress. In recent years, renewed interest in psychedelic medicine has highlighted the therapeutic potential of psilocybin for those who have experienced childhood adversity. However, recreational psilocybin use remains illegal and access to approved therapies is difficult. Such use provides an opportunity to...

Safety and tolerability of intramuscular and sublingual ketamine for psychiatric treatment in the Roots To Thrive ketamine-assisted therapy program: a retrospective chart review.

Therapeutic Advances in Psychopharmacology 2023 Vivian W. L. Tsang, Brendan Tao, Shannon Dames et al. 19 citations

In the last few years, ketamine is becoming increasingly common in the treatment of mental health conditions, but there is a lack of safety data informing intramuscular and sublingual dosing in a community-focused group psychotherapy setting. The Roots To Thrive ketamine-assisted therapy (RTT-KaT) program is a unique 12-week RTT-KaT program with 12 community of practice (a form of group...

Author Correction: Psilocybin microdosers demonstrate greater observed improvements in mood and mental health at one month relative to non-microdosing controls.

Sci Rep July 28, 2022 Joseph M. Rootman, Maggie Kiraga, Pamela Kryskow et al. 2 citations

Author Correction: Psilocybin microdosers demonstrate greater observed improvements in mood and mental health at one month relative to non-microdosing controls.

Psilocybin microdosers demonstrate greater observed improvements in mood and mental health at one month relative to non-microdosing controls

Scientific Reports June 30, 2022 Joseph M. Rootman, Maggie Kiraga, Pamela Kryskow et al. 53 citations

Abstract Psilocybin microdosing involves repeated self-administration of mushrooms containing psilocybin at doses small enough to not impact regular functioning. Microdose practices are diverse and include combining psilocybin with substances such as lion’s mane mushrooms (Hericium erinaceus; HE) and niacin (vitamin-B3). Public uptake of microdosing has outpaced evidence, mandating further...

Ketamine for the treatment of mental health and substance use disorders: comprehensive systematic review - CORRIGENDUM.

BJPsych Open January 18, 2022 Zach Walsh, Özden Merve Mollaahmetoğlu, Joseph M. Rootman et al. 28 citations

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Ketamine for the treatment of mental health and substance use disorders: comprehensive systematic review

BJPsych Open December 23, 2021 Zach Walsh, Özden Merve Mollaahmetoğlu, Joseph M. Rootman et al. 180 citations

Background In the past two decades, subanaesthetic doses of ketamine have been demonstrated to have rapid and sustained antidepressant effects, and accumulating research has demonstrated ketamine's therapeutic effects for a range of psychiatric conditions. Aims In light of these findings surrounding ketamine's psychotherapeutic potential, we systematically review the extant evidence on...

Adults who microdose psychedelics report health related motivations and lower levels of anxiety and depression compared to non-microdosers

Scientific Reports November 18, 2021 Joseph M. Rootman, Pamela Kryskow, Kalin Harvey et al. 78 citations

Abstract The use of psychedelic substances at sub-sensorium ‘ microdoses’, has gained popular academic interest for reported positive effects on wellness and cognition. The present study describes microdosing practices, motivations and mental health among a sample of self-selected microdosers ( n = 4050) and non-microdosers ( n = 4653) via a mobile application. Psilocybin was the most commonly...

Psychedelic-Assisted Psychotherapy After COVID-19: The Therapeutic Uses of Psilocybin and MDMA for Pandemic-Related Mental Health Problems

Frontiers in Psychiatry September 6, 2021 Elena Argento, Devon Christie, Lindsay Mackay et al. 12 citations

The COVID-19 pandemic stands to have impacts on mental health and well-being that will extend beyond its formal resolution. Before COVID-19, mental health disorders were already challenging global healthcare systems, directly accounting for 7.4% of the total burden of disease (1, 2). An estimated 1 billion people worldwide suffer from a mental health disorder, with the two most common...

MDMA-assisted psychotherapy for treatment of PTSD: study design and rationale for phase 3 trials based on pooled analysis of six phase 2 randomized controlled trials.

Psychopharmacology September 1, 2019 Michael C Mithoefer, Allison A. Feduccia, Lisa Jerome et al. 364 citations Retracted

Posttraumatic stress disorder is a prevalent mental health condition with substantial impact on daily functioning that lacks sufficient treatment options. Here we evaluate six phase 2 trials in a pooled analysis to determine the study design for phase 3 trials of MDMA-assisted psychotherapy for PTSD. Six randomized, double-blind, controlled clinical trials at five study sites were conducted...

Psychedelics and the new behaviourism: considering the integration of third-wave behaviour therapies with psychedelic-assisted therapy

International Review of Psychiatry July 4, 2018 Zach Walsh, Michelle S. Thiessen 65 citations

This narrative review examines evidence related to the potential for third wave behaviour therapies to serve as adjuncts to psychedelic-assisted therapy. It identifies shared theoretical foundations for both approaches, and notes enhanced mindfulness, decentering, emotion regulation, and distress tolerance as common mechanisms of action. It also identifies potential targets for which both...

Psychedelic use and intimate partner violence: The role of emotion regulation

Journal of Psychopharmacology May 29, 2018 Michelle S. Thiessen, Zach Walsh, Brian M. Bird et al. 58 citations

Background: Recent evidence suggests that psychedelic use predicts reduced perpetration of intimate partner violence among men involved in the criminal justice system. However, the extent to which this association generalizes to community samples has not been examined, and potential mechanisms underlying this association have not been directly explored. Aims: The present study examined the...

The relationships of classic psychedelic use with criminal behavior in the United States adult population

Journal of Psychopharmacology October 17, 2017 Peter S. Hendricks, Michael S Crawford, Karen L. Cropsey et al. 91 citations

Criminal behavior exacts a large toll on society and is resistant to intervention. Some evidence suggests classic psychedelics may inhibit criminal behavior, but the extent of these effects has not been comprehensively explored. In this study, we tested the relationships of classic psychedelic use and psilocybin use per se with criminal behavior among over 480,000 United States adult...

Hallucinogen use and intimate partner violence: Prospective evidence consistent with protective effects among men with histories of problematic substance use

Journal of Psychopharmacology April 19, 2016 Zach Walsh, Peter S. Hendricks, Stephanie D. Smith et al. 63 citations

Evidence suggests that hallucinogens may have therapeutic potential for addressing a variety of problem behaviors related to the externalizing spectrum of psychopathology, such as substance misuse and criminality. Intimate partner violence (IPV) is a prevalent form of criminal violence that is related to externalizing pathology. However, the association between hallucinogen use and IPV has not...