Trials
April 23, 2021
Robin J. Murphy, Rachael L. Sumner, William J. Evans et al.
23 citations
A proposed study will test whether regular low doses of LSD, known as microdosing, produce the cognitive and emotional benefits reported anecdotally. Eighty healthy men will receive either a placebo or 10 micrograms of LSD every third day for six weeks. The study will measure personality, creativity, mood, cognition, brain plasticity, and brain imaging at baseline and after the protocol, with additional acute measures after the first dose. Daily functioning will be tracked via questionnaires and a wearable device. The goal is to rigorously evaluate microdosing claims using objective measures, with potential future applications for treating depression, addiction, and other conditions.
Neuropharmacology
November 5, 2025
Dimitri Daldegan‐bueno, C Donegan, Rachael L. Sumner et al.
4 citations
In an open-label phase 2A trial, 19 participants with major depressive disorder, most of whom were taking antidepressants, took microdoses of LSD twice weekly for eight weeks. No serious adverse events occurred, and one participant withdrew due to anxiety. Depression scores on the Montgomery-Åsberg Depression Rating Scale dropped by 59.5% at the end of the intervention, with improvements sustained for up to six months. Anxiety, rumination, stress, and quality of life also improved. The results provide preliminary evidence that microdosed LSD is safe and feasible for treating moderate depression, but randomized controlled trials are needed.
Progress in Neuro-Psychopharmacology and Biological Psychiatry
February 18, 2026
Dimitri Henriques Daldegan-Bueno, C Donegan, Rachael L. Sumner et al.
1 citation
Taking very low doses of LSD (8 micrograms) repeatedly over a short period may temporarily improve mood in people with depression, though the effect needs confirmation in controlled experiments. The drug's behavior in the body was measured in this group, and no evidence of tolerance or increased sensitivity appeared, even when the dose was gradually increased.
Ther Adv Psychopharmacol
December 4, 2025
Carina Joy Donegan, Dimitri Daldegan-Bueno, Rachael L. Sumner et al.
People with depression who microdosed LSD described their experiences in interviews from an open-label trial. The analysis identified themes such as improved mood, increased energy, and greater emotional openness, though some participants also reported anxiety or discomfort. The findings suggest that microdosing may offer benefits for some individuals, but the open-label design means results should be interpreted cautiously.
Journal of Humanistic Psychology
November 10, 2025
Robin J. Murphy, Mia Wardlaw, Thomas A. Smith et al.
After a six-week double-blind placebo-controlled trial of 10 µg of lysergic acid diethylamide taken every third day, healthy male participants reported changes in emotions, mood, social life, mindfulness, cognition, work, creativity, and physiological effects. Openness to experience and bidirectionality of effects were overarching themes. Some reported changes have potential clinical relevance for mood disorders, and reports of changes in anxiety suggest careful patient and dose selection. Participants' experiences with set and setting, uncertainty from placebo control, and perceived bidirectionality of effects inform psychedelic clinical trial design.
medRxiv
August 7, 2025
Ben Deverett, Duan Li, Theresa R. Lii et al.
preprint
Ketamine produces dissociative, analgesic, and antidepressant effects, but it is unclear whether its underlying neurophysiological signatures can be separated. In this observational cohort study, 52 participants (healthy volunteers, elective surgery patients, and patients with depression) received a subanesthetic infusion of ketamine or placebo, with or without general anesthesia. When ketamine was given under general anesthesia, its characteristic low-frequency brain wave augmentation was absent, while high-frequency power modulation was preserved. This selective modulation suggests a method for investigating the distinct roles of high- and low-frequency neural activity in ketamine's behavioral effects.
July 25, 2025
Rachael L. Sumner, Yuxin Ni, Suresh Muthukumaraswamy
preprint
People with premenstrual dysphoric disorder (PMDD) microdose psilocybin to manage their symptoms, and all 14 interview participants reported benefit, though their regimens and treatment goals varied widely. PMDD is a severe mood disorder with limited treatment options. Participants described how PMDD harmed their quality of life and why they turned to microdosing. The findings suggest clinical trials into microdosing psychedelics for PMDD are warranted, as current information to support people engaging in this practice is lacking.