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Tommaso Barba

13 papers in the library · 346 citations · publishing 2022-2026

Papers

Psychedelic therapy in the treatment of addiction: the past, present and future

Frontiers in Psychiatry June 12, 2023 Rayyan Zafar, Maxim Siegel, Rebecca Harding et al. 95 citations

Psychedelic therapy is regaining scientific and medical interest, with growing evidence for its safety and efficacy in treating psychiatric disorders, including addiction. This review charts research on these interventions for addiction, starting with the socioeconomic impact of addiction and current treatment options. It examines historical studies from the mid-late 1900s, real-world evidence from naturalistic and survey-based studies, and modern clinical trials from first-in-human to phase II. The review also covers translational neuropsychopharmacology techniques like fMRI and PET that help explain therapeutic mechanisms. A better understanding of these treatment effects can optimize psychedelic therapy development and improve patient outcomes.

Effects of psilocybin versus escitalopram on rumination and thought suppression in depression

BJPsych Open September 1, 2022 Tommaso Barba, Sarah Buehler, Hannes Kettner et al. 57 citations

Psilocybin, but not the antidepressant escitalopram, reduced rumination and thought suppression in people with major depressive disorder six weeks after treatment. In a randomized trial of 59 participants, only those given psilocybin showed significant decreases in both maladaptive coping strategies. Among treatment responders, thought suppression decreased exclusively in psilocybin responders, while rumination decreased in both psilocybin and escitalopram responders. Reductions in rumination and thought suppression correlated with ego dissolution and psychological insight during psilocybin sessions, suggesting distinct therapeutic mechanisms for the two treatments.

Effect of psilocybin versus escitalopram on depression symptom severity in patients with moderate-to-severe major depressive disorder: observational 6-month follow-up of a phase 2, double-blind, randomised, controlled trial

EClinicalMedicine September 23, 2024 David Erritzøe, Tommaso Barba, Kyle T Greenway et al. 46 citations

In a clinical trial, psilocybin therapy showed comparable effectiveness to a common SSRI antidepressant for treating depression, with both treatments leading to significant reductions in depressive symptoms over a follow-up period. The findings suggest psilocybin may offer a viable alternative to standard antidepressant medication, though the study's design and sample size limit the strength of conclusions.

Interactions between classic psychedelics and serotonergic antidepressants: Effects on the acute psychedelic subjective experience, well-being and depressive symptoms from a prospective survey study.

J Psychopharmacol January 27, 2024 Jessica Barbut Siva, Tommaso Barba, Hannes Kettner et al. 29 citations

A prospective survey study examined how serotonergic antidepressants affect the acute subjective experience of classic psychedelics and subsequent well-being and depressive symptoms. People taking antidepressants reported less intense mystical-type experiences and greater anxiety during psychedelic sessions compared to those not on antidepressants. Despite this blunting, both groups showed similar improvements in well-being and reductions in depressive symptoms after the session. The findings suggest that while antidepressants may dampen the acute psychedelic experience, they do not necessarily hinder long-term mental health benefits.

Effects of discontinuation of serotonergic antidepressants prior to psilocybin therapy versus escitalopram for major depression

Journal of Psychopharmacology March 22, 2024 Tommaso Barba, David Erritzøe, Meg J. Spriggs et al. 26 citations

In a clinical trial comparing psilocybin plus psychological support to escitalopram plus psychological support for major depressive disorder, patients who discontinued their SSRI or SNRI medication before receiving psilocybin showed a reduced treatment effect on all depression severity and well-being measures compared with those who were unmedicated at trial entry. Discontinuation did not affect the intensity of the acute psychedelic experience. The findings are exploratory and hypothesis-generating, not confirmatory, and the study did not test SSRI/SNRI continuation. A controlled trial comparing discontinuation versus continuation before psilocybin is needed.

Psychedelics and sexual functioning: a mixed-methods study

Scientific Reports February 7, 2024 Tommaso Barba, Hannes Kettner, Caterina Radu et al. 24 citations

Psychedelics may improve sexual functioning and satisfaction days or weeks after use, according to two studies. In a large naturalistic study, people who used psychedelics reported greater pleasure, communication during sex, and satisfaction with their partner and appearance. A controlled clinical trial comparing psilocybin therapy with the SSRI escitalopram for depression found that those given psilocybin reported positive changes in sexual functioning after treatment, while those given escitalopram did not. This is the first quantitative investigation of psychedelics' post-acute effects on sexual functioning, suggesting a potential benefit and a need for further research.

Exploring 5-MeO-DMT as a pharmacological model for deconstructed consciousness.

Neuroscience of consciousness January 1, 2025 Christopher Timmermann, James W Sanders, David Reydellet et al. 19 citations

The psychedelic 5-MeO-DMT can, in its most extreme cases, produce a complete absence of self-experience and other perceptual content while preserving a quality of aroused, waking awareness. In an exploratory observational study in naturalistic ceremonial settings, micro-phenomenological interviews, questionnaires, and EEG recordings revealed a dynamic progression of effects, including variable disruptions of bodily and narrative self, reduced phenomenal distinctions, and visual imagery. EEG showed global alpha and posterior beta power reductions, suggesting inhibition of top-down brain models. The findings indicate 5-MeO-DMT's potential as a pharmacological model for deconstructed consciousness, though retrospective questionnaires have limitations.

Psychedelics and the ‘inner healer’: Myth or mechanism?

Journal of Psychopharmacology April 12, 2024 Joseph Peill, Miriam Marguilho, David Erritzøe et al. 16 citations

In a double-blind randomized controlled trial, 59 patients with depression received either a high (25 mg) or placebo (1 mg) dose of psilocybin. Those given the high dose reported stronger perceived 'inner healing' effects, and within that group, higher inner healer scores predicted greater improvement in depressive symptoms two weeks later. The findings suggest that the concept of an intrinsic healing mechanism activated by psychedelics merits further scientific investigation, though the idea remains scientifically nascent.

Safety, tolerability, pharmacodynamic and wellbeing effects of SPL026 (dimethyltryptamine fumarate) in healthy participants: a randomized, placebo-controlled phase 1 trial.

Frontiers in psychiatry January 1, 2023 Ellen James, David Erritzøe, Tiffanie Benway et al. 16 citations

A phase 1 trial tested escalating intravenous doses of the psychedelic DMT (SPL026) in healthy volunteers who had never used psychedelics, to find a safe, tolerable dose for a future trial in people with major depressive disorder. Participants were randomly assigned to placebo or one of four doses (9, 12, 17, or 21.5 mg). The drug was well tolerated with no serious adverse events. Higher blood levels of DMT correlated with stronger ratings of mystical experience, ego dissolution, and intensity, though these trends need confirmation in larger studies. Based on safety and pharmacodynamic results, 21.5 mg given as a two-phase infusion was chosen for the patient trial.

Study protocol for “Psilocybin in patients with fibromyalgia: brain biomarkers of action”

Frontiers in Psychiatry June 4, 2024 Julia Bornemann, James B Close, Kirran Ahmad et al. 11 citations

Psilocybin-assisted therapy may help treat fibromyalgia, a chronic widespread pain condition with limited treatment options. A protocol describes a mechanistic study with 20 participants who will attend 8 visits over 8 weeks, including two dosing sessions where psilocybin is given at least once, with doses up to 25 mg. The primary focus is on brain mechanisms, measured via electroencephalography during the acute psychedelic state and magnetic resonance imaging before and after treatment. Primary outcomes are Lempel-Ziv complexity from EEG and experiential avoidance via questionnaire. Secondary measures include pain, physical and mental function, and additional neuroimaging. Results aim to clarify how psilocybin-therapy works in the brain and inform a future randomized controlled trial.

A short-acting psychedelic intervention for major depressive disorder: a phase IIa randomized placebo-controlled trial.

Nat Med February 16, 2026 David Erritzøe, Tommaso Barba, Tiffanie Benway et al. 4 citations

A single 21.5-mg intravenous dose of the psychedelic DMT, given with psychotherapeutic support, produced a rapid and significant reduction in depressive symptoms in adults with moderate-to-severe major depressive disorder. In a double-blind, placebo-controlled trial with 34 participants, those receiving DMT showed a greater decrease in depression scores at two weeks compared to placebo. Antidepressant effects persisted up to three months in an open-label phase. Adverse events were mostly mild to moderate, and no serious adverse events occurred.

Neuroimaging and the Investigation of Drug-Drug Interactions Involving Psychedelics.

Neurosci Insights October 8, 2024 Matthew B Wall, Rebecca Harding, Natalie Ertl et al. 3 citations

Psychedelic therapies are new psychiatric treatments that may need to be combined with existing medications, but little is known about their interactions with common psychiatric drugs. This commentary reviews key findings on such drug-drug interactions and proposes that multimodal neuroimaging, combining PET and fMRI with other measures, offers the most thorough way to study these interactions across molecular, functional, and clinical levels.

Neural effects and phenomenology of nondual meditation and 5-MeO-DMT in an expert meditation practitioner

PsyArXiv September 30, 2025 Christopher Timmermann, Tommaso Barba, James Sanders et al. preprint

In an advanced meditator and Lama from the Mahāmudrā tradition, nondual meditation and a low dose (5 mg) of 5-MeO-DMT both produced timelessness, reduced labeling of sensory content, and diminished narrative self and thoughts. Both states showed increased alpha power and decreased gamma power in the brain, with neural overlap driven by posterior and right frontal gamma reductions. Nondual meditation uniquely emphasized recognition of nonduality and clarity of mind, while low-dose 5-MeO-DMT was characterized by visual imagery. High-dose (12 mg) 5-MeO-DMT produced sensory disconnection, seeing a 'white-light', and broad increases in gamma power. The findings suggest two distinct routes to self-dissolution: a 'saturation' route with increased neural firing and entropy (high-dose 5-MeO) and a 'subtractive' route with reduced firing and entropy (nondual meditation and low-dose 5-MeO).