Skip to content

Richard Zeifman

5 papers in the library · 24 citations · publishing 2022-2026

Papers

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.

Psychiatric risks for worsened mental health after psychedelic use

PsyArXiv October 17, 2023 Alessia Marrocu, Hannes Kettner, Brandon Weiss et al. 9 citations preprint

About 16% of people who used psychedelics in naturalistic settings experienced a clinically meaningful decline in psychological well-being four weeks later. Those with a prior personality disorder diagnosis were disproportionately affected, making up 31% of negative responders and facing more than a four-fold elevated risk of adverse psychological responses. The findings suggest that personality disorders may heighten vulnerability to negative outcomes from psychedelic use, highlighting the need for careful screening and robust psychological support.

How Does Psilocybin Therapy Work? an Exploration of Experiential Avoidance as a Putative Mechanism of Change

June 17, 2024 Richard Zeifman 1 citation

Psilocybin therapy may improve mental health by reducing experiential avoidance—the tendency to suppress or avoid distressing thoughts and feelings. In a quasi-experimental study with 28 healthy individuals, a high dose (25 mg) of psilocybin led to significant reductions in experiential avoidance at 2 and 4 weeks, sustained at 3 months but not at 6 months, while a very low dose (1 mg) did not. These reductions predicted improvements in well-being and decreases in depressed and anxious mood. In a randomized controlled trial with 59 people with major depressive disorder, psilocybin therapy reduced experiential avoidance more than the antidepressant escitalopram, and these reductions indirectly improved well-being, depression severity, suicidal ideation, and trait anxiety. The findings suggest experiential avoidance is a key mechanism in psilocybin therapy's effects.

On the meaning of ‘plasticity’ in neuroscience and mental health research and its relation to the action of psychedelic therapy

May 13, 2026 Robin Carhart-Harris, Richard Zeifman, Lorenzo Pasquini et al. preprint

The paper argues that the term 'plasticity' in neuroscience refers to induced changes in brain function or structure, which differs from the dictionary definition of plasticity as the ability to be shaped or molded. Many biomarkers of neuroplasticity actually index processes that bias phenotypic canalization, the opposite of phenotypic plasticity, creating a paradox. The authors question extrapolating from these biomarkers to improved mental health, as the relationship is context dependent. They propose a new construct, 'mediational and recalibrative plasticity' (MR-P), which aligns with plasticity proper and can describe and predict phenotypic changes relevant to mental health.

Safety and Efficacy of Psilocybin-Assisted Therapy for Alcohol Use Disorder: Open-Label Extension of a Phase II Randomized Controlled Trial

PsyArXiv March 26, 2026 Broc A Pagni, Stephen Ross, Sarah Mennenga et al. preprint

An open-label extension of a Phase II randomized controlled trial examined the safety and efficacy of psilocybin-assisted therapy for alcohol use disorder. Participants who had received either psilocybin or placebo in the main trial were offered two open-label psilocybin sessions. The treatment was well tolerated, with no serious adverse events attributed to psilocybin. Heavy drinking days decreased substantially from baseline, and the reduction was sustained through the 32-week follow-up. The findings suggest that psilocybin-assisted therapy may produce durable reductions in alcohol consumption among individuals with alcohol use disorder.