JAMA Psychiatry
June 1, 2026
Ben Deverett, Duan Li, Theresa R. Lii et al.
1 citation
Ketamine has well-known dissociative, analgesic, and antidepressant properties, but it is unknown whether the neurophysiologic effects that are associated with these properties can be modulated separately from one another. Considering that specific cortical oscillations have been associated with specific therapeutic effects, modulating selective aspects of ketamine neurophysiology could inform...
Progress in Neuro-psychopharmacology and Biological Psychiatry
February 18, 2026
Dimitri Henriques Daldegan-Bueno, C Donegan, Rachael Sumner et al.
1 citation
Results suggest short-term improvements in mood following microdosed LSD in people with depression, warranting confirmation in controlled trials. It provides the pharmacokinetic parameters of 8 μg of LSD in a sample of people with depression and indicates no tolerance or sensitisation to repeated microdoses of LSD, despite incremental dose titration.
Ther Adv Psychopharmacol
December 4, 2025
Carina Joy Donegan, Dimitri Daldegan-Bueno, Rachael Sumner et al.
What is it like to microdose LSD for depression? a thematic analysis of participant interviews from an open-label trial.
Neuropharmacology
December 1, 2025
Carina Joy Donegan, Dimitri Daldegan-Bueno, Tehseen Noorani et al.
4 citations
Expectations can impact antidepressant treatment and psychedelic therapy, often enhancing placebo effects and influencing outcomes. However, research in this context is lacking. Our study explored the expectations of participants with major depressive disorder (MDD) before microdosing lysergic acid diethylamide (LSD) in an open-label trial. Twenty-three individuals with MDD completed a...
Journal of Chromatographic Science
November 15, 2025
Mahima Bansal, Estelle Miller, Rachael Sumner et al.
With the rising interest in therapeutic potential of microdosing lysergic acid diethylamide (LSD), accurate quantification and stability analysis are imperative for both scientific research and end-user safety. Currently, high throughput quantification of LSD in clinical microdosing formulations and community sourced microdosing samples remain a challenge due to the absence of fast analytical...
Journal of Humanistic Psychology
November 10, 2025
Robin J Murphy, Mia Wardlaw, Thomas A. Smith et al.
Microdosing psychedelics is an increasingly popular phenomenon where small amounts of psychedelic drugs are taken regularly. Qualitative data have been published regarding the experiences of microdosers, but never in the context of a randomised controlled trial. Semi-structured video interviews with 40 healthy males were conducted following a double-blind placebo-controlled trial of 10 µg of...
Neuropharmacology
November 5, 2025
Dimitri Daldegan-Bueno, C Donegan, Rachael Sumner et al.
4 citations
Major depressive disorder (MDD) affects approximately 5 % of the global population. Classic psychedelics have shown promise in treating various mental health disorders. This study evaluated the feasibility and tolerability of an 8-week regimen of microdosed lysergic acid diethylamide (LSD) as a treatment for major depressive disorder in an open-label phase 2A trial (LSDDEP1). Nineteen...
medRxiv
August 7, 2025
Ben Deverett, Duan Li, Theresa R. Lii et al.
preprint
Structured Abstract Importance Ketamine has well known dissociative, analgesic, and antidepressant properties, but it is unknown whether the neurophysiologic effects that are associated with these properties can be modulated separately from one another. Given prior studies that link specific cortical oscillations with specific therapeutic effects, it is likely that modulating selective aspects...
The International Journal of Neuropsychopharmacology
August 1, 2025
C Donegan, D Daldagen-Bueno, Robin J Murphy et al.
Abstract Background Depressive disorders affect about 280 million people worldwide, with many struggling to find effective relief. Conventional antidepressants are widely prescribed but often lack efficacy and have side effects, leaving many patients dissatisfied or untreated. Concurrently, psychedelic therapies have gained momentum in both research and ‘in the wild’, with emerging evidence...
July 25, 2025
Rachael Sumner, Yuxin Ni, Suresh Muthukumaraswamy
preprint
Background: Premenstrual dysphoric disorder (PMDD) is a severe mood disorder characterised by depression, irritability, mood lability, anxiety and physical symptoms that occur exclusively in the last week/s of the menstrual cycle. With a growing global interest in microdosing of psychedelic drugs, an increase in self-medication has occurred, including by those with PMDD. Aim: Qualitative...
Journal of psychopharmacology (Oxford, England)
April 18, 2025
James D Morse, Soo Hee Jeong, Robin J Murphy et al.
3 citations
Microdosing is the practice of taking psychedelic drugs at doses that produce no or minimal perceptible subjective or behavioural effects. This study investigated the pharmacokinetics and pharmacodynamics of microdosed lysergic acid diethylamide (LSD). This was a Phase 1 double-blind placebo-controlled parallel-groups trial with 80 healthy male volunteers (four withdrawals due to anxiety)....
Psychopharmacology
February 1, 2025
Robin J Murphy, Rachael Sumner, Kate Godfrey et al.
9 citations
Enhanced creativity is often cited as an effect of microdosing (taking repeated low doses of a psychedelic drug). There have been recent efforts to validate the reported effects of microdosing, however creativity remains a difficult construct to quantify. The current study aimed to assess microdosing's effects on creativity using a multimodal battery of tests as part of a randomised controlled...
Translational Psychiatry
April 15, 2024
Nathan Allen, Aron Jeremiah, Robin J Murphy et al.
15 citations
Microdosing psychedelic drugs at a level below the threshold to induce hallucinations is an increasingly common lifestyle practice. However, the effects of microdosing on sleep have not been previously reported. Here, we report results from a Phase 1 randomized controlled trial in which 80 healthy adult male volunteers received a 6-week course of either LSD (10 µg) or placebo with doses...
Translational Psychiatry
February 24, 2024
Rachael Sumner, Rebecca McMillan, Anna Forsyth et al.
7 citations
Revealing the acute cortical pharmacodynamics of an antidepressant dose of ketamine in humans with depression is key to determining the specific mechanism(s) of action for alleviating symptoms. While the downstream effects are characterised by increases in plasticity and reductions in depressive symptoms-it is the acute response in the brain that triggers this cascade of events. Computational...
BMC Neuroscience
February 5, 2024
Robin J Murphy, Kate Godfrey, Alexander D Shaw et al.
16 citations
Microdosing psychedelics is a phenomenon with claimed cognitive benefits that are relatively untested clinically. Pre-clinically, psychedelics have demonstrated enhancing effects on neuroplasticity, which cannot be measured directly in humans, but may be indexed by non-invasive electroencephalography (EEG) paradigms. This study used a visual long-term potentiation (LTP) EEG paradigm to test the...
Pilot and Feasibility Studies
October 5, 2023
Carina Joy Donegan, Dimitri Daldegan-Bueno, Rachael Sumner et al.
23 citations
Globally, an estimated 260 million people suffer from depression [1], and there is a clear need for the development of new, alternative antidepressant therapies. In light of problems with the tolerability and efficacy of available treatments [2], a global trend is emerging for patients to self-treat depression with microdoses of psychedelic drugs such as lysergic acid diethylamide (LSD) and...
Biological Psychiatry
September 15, 2023
Robin J Murphy, Rachael Sumner, William Evans et al.
69 citations
Microdosing psychedelic drugs is a widespread social phenomenon with diverse benefits claimed for mood and cognition. Randomized controlled trials have failed to support these claims, but the laboratory-based dosing in trials conducted to date may have limited ecological validity. Healthy male volunteers were randomized into lysergic acid diethylamide (LSD) (n = 40) and placebo (n = 40) groups...
BMC Neurosci
June 30, 2023
Rachael Sumner, Kacper Łukasiewicz
6 citations
When it comes to studying neural plasticity and psychedelics, the numerous and diverse neuroscientific fields converging on the topic provide unique insight into a complex picture. This editorial will describe the major ways in which the known effects of psychedelics on plasticity are being studied. We lay out strengths of different techniques and the major gaps and room for future research,...
Molecular Psychiatry
September 7, 2022
Rebecca B Price, Nicholas Kissel, Andrew Baumeister et al.
80 citations
Abstract Depression is disabling and highly prevalent. Intravenous (IV) ketamine displays rapid-onset antidepressant properties, but little is known regarding which patients are most likely to benefit, limiting personalized prescriptions. We identified randomized controlled trials of IV ketamine that recruited individuals with a relevant psychiatric diagnosis (e.g., unipolar or bipolar...
Australian & New Zealand Journal of Psychiatry
March 4, 2022
Suresh Muthukumaraswamy, Anna Forsyth, Rachael Sumner
59 citations
With the extensive public, commercial and scientific interest from what has been widely termed the psychedelic renaissance, it is important that the scientific practices and results obtained from its implementation into medicine are put under a critical microscope. While there are numerous works on the potential benefits and applications of psychedelics as medicines, relatively little has been...
Journal of psychopharmacology (Oxford, England)
August 1, 2021
Rachael Sumner, Emme Chacko, Rebecca McMillan et al.
68 citations
Ketamine is central to one of the most rapidly growing areas of neuroscientific research into novel treatments for depression. Limited research has indicated that the psychedelic properties of ketamine may play a role in its antidepressant effects. The aim of the current study was to explore the psychedelic experiences and sustained impact of ketamine in major depressive disorder. In the...
Trials
April 23, 2021
Robin J Murphy, Rachael Sumner, William Evans et al.
23 citations
BACKGROUND: Regular ingestion of sub-hallucinogenic doses of psychedelics, referred to as "microdosing", has gained increasing popularity and attention in the press and in online forums, with reported benefits across multiple cognitive and emotional domains. Rigorously controlled studies to date, however, have been limited in scope and have failed to produce results comparable to those reported...
bioRxiv Preprint Server
May 5, 2020
Alexander D Shaw, Suresh Muthukumaraswamy, Neeraj K. Saxena et al.
2 citations
preprint
Cortical recordings of task-induced oscillations following subanaesthetic ketamine administration demonstrate alterations in amplitude, including increases at high-frequencies (gamma) and reductions at low frequencies (theta, alpha). To investigate the population-level interactions underlying these changes, we implemented a thalamo-cortical model (TCM) capable of recapitulating broadband...