Journal of psychopharmacology (Oxford, England)
August 1, 2021
Rachael L Sumner, Emme Chacko, Rebecca McMillan et al.
68 citations
Ketamine, given at 0.44 mg/kg to 32 volunteers with major depressive disorder in a crossover design with the active-placebo remifentanil, produced psychedelic experiences that correlated with greater antidepressant response at 24 hours. Specifically, higher scores on spirituality, experience of unity, and insight were linked to larger reductions in depression ratings. Qualitative interviews revealed perceptual changes, loss of control, emotional shifts, a psychedelic afterglow, and lasting changes in perspective on life, people, problems, and depression. The findings suggest the psychedelic experience and afterglow contribute to ketamine's antidepressant effects, and that standard questionnaires may not fully capture these properties.
International Journal of Environmental Research and Public Health
August 2, 2021
Lisa Reynolds, Amelia Akroyd, Frederick Sundram et al.
33 citations
Cancer healthcare professionals—doctors, nurses, psychologists, and social workers—show openness to psychedelic-assisted therapy for advanced cancer patients, driven by a desire to alleviate suffering and a lack of effective current treatments. However, this openness is tempered by concerns about patient safety and the need for rigorous, well-designed trials. The study identified four themes: beneficence (alleviating suffering), non-maleficence (keeping vulnerable patients safe), viewing psychedelic-assisted therapy as a transformative approach with real potential, and recognizing that new frontiers carry risks. These findings offer a foundation for engaging healthcare professionals in future research and clinical applications.
Pilot and feasibility studies
October 5, 2023
Carina Joy Donegan, Dimitri Daldegan-Bueno, Rachael Sumner et al.
23 citations
An estimated 260 million people worldwide have depression, and many self-treat with microdoses of psychedelics like LSD and psilocybin despite limited clinical evidence. A prior phase 1 study in healthy volunteers found LSD microdosing safe, well tolerated, and feasible with good adherence. This open-label pilot trial (LSDDEP1) will test tolerability and feasibility of an 8-week LSD microdosing regimen in 20 patients with major depressive disorder. Participants receive a sublingual LSD formulation (MB-22001) twice weekly at 5–15 µg. Tolerability is measured by withdrawal due to adverse events; feasibility by clinic visit attendance. Antidepressant response will be assessed with MADRS scores over 8 weeks. Results will inform a future randomized controlled trial.
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.
Palliative & Supportive Care
November 3, 2022
Lisa Reynolds, Brian S. Barnett, Jeremy Weleff et al.
19 citations
Cancer health-care practitioners in New Zealand and the USA perceive psychedelic-assisted therapy as potentially beneficial for cancer patients, especially those with advanced disease no longer receiving curative treatment. They consider research in this area important and express willingness to refer patients to trials, though they emphasize that work should incorporate spiritual and indigenous perspectives of health. US practitioners had greater awareness of psychedelics, while New Zealand practitioners more strongly believed that spiritual and indigenous factors should be considered. The findings suggest that practitioners may be more open to studies beginning in palliative and end-of-life contexts.
Translational psychiatry
April 15, 2024
Nathan Allen, Aron Jeremiah, Robin Murphy et al.
15 citations
Microdosing LSD (10 µg every third day for six weeks) increased sleep duration in healthy adult male volunteers. On nights after dosing, the LSD group slept an extra 24.3 minutes per night compared to placebo, with no change in sleep on dosing days. Sleep stage proportions and physical activity remained unchanged. The findings indicate that microdosing LSD modifies physiological sleep requirements, and the objective changes are unlikely to be a placebo effect.
Trials
August 24, 2024
Dimitri Daldegan-Bueno, Carina Joy Donegan, Anna Forsyth et al.
14 citations
A phase 2b randomized controlled trial will test whether repeated low doses of LSD (4 to 20 micrograms, taken twice weekly for 8 weeks at home) reduce depressive symptoms in people with major depressive disorder, compared to an active placebo. The trial is triple-blind and includes measures of mood, personality, sleep, brain activity, blood biomarkers, and safety. This is the first controlled trial to test microdosed LSD in patients' natural environment. Results will help determine whether psychedelic microdosing is a viable additional treatment for depression and guide future research.
Pilot and feasibility studies
February 12, 2024
Alesha Wells, A P Suresh Muthukumaraswamy, Eva Morunga et al.
10 citations
A proposed trial will test whether adding a low, non-hallucinogenic dose of LSD to meaning-centred psychotherapy (MCP) is feasible for advanced cancer patients with anxiety or depression. Forty participants (20 Māori, 20 non-Māori) will receive seven MCP sessions plus either an LSD microdose (4-20 µg) or a placebo, under double-blind conditions. Outcomes include feasibility, acceptability, safety, and psychological measures at baseline, during treatment, and at one- and six-month follow-ups. The study aims to determine whether a full-scale trial is possible and to provide initial evidence on whether microdosing may enhance psychological care in this population.
Psychopharmacology
February 1, 2025
Robin J Murphy, Rachael L Sumner, Kate Godfrey et al.
9 citations
A randomized controlled trial gave 80 healthy adult males 10 µg doses of LSD or placebo every third day for six weeks and tested creativity with the Alternate Uses Test, Remote Associates Task, Consensual Assessment Technique, and an Everyday Problem-Solving Questionnaire. No drug effect was found on any creativity measure at the first dose or after six weeks, despite participants reporting feeling more creative on dose days. Baseline vocabulary skill significantly influenced scores on two tests. The null findings may reflect that laboratory testing misses naturalistic creative differences, available tests do not capture the facets of creativity anecdotally affected, or reported enhancements are placebo effects.
Neuropharmacology
December 1, 2025
Carina Joy Donegan, Dimitri Daldegan-Bueno, Tehseen Noorani et al.
4 citations
Before starting a low-dose LSD regimen, people with major depression held varied expectations shaped largely by media and personal experience. Over half had tried other treatments that failed. Many expected subtle effects or had no specific expectations, while some anticipated changes in consciousness or neural rewiring. Hope served both as a motivator and a buffer against disappointment. The findings underscore how media influences expectations and suggest that current expectancy measures miss important factors specific to psychedelic therapy.
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.
The International Journal of Neuropsychopharmacology
August 1, 2025
C Donegan, D Daldagen-Bueno, Robin J. Murphy et al.
In an open label trial, 17 people with major depressive disorder took 15 doses of LSD at home and one in a clinic over 8 weeks. Afterward, participants reported increased connectedness to self, others, and nature; greater motivation for activities; improved mood; and better coping with negative situations. Some experienced side effects or no change in symptoms. The findings suggest that microdosing LSD may create a positive feedback loop where improved mood, behavioral activation, and connectedness reinforce each other, and that adding a titration protocol and encouraging psychologically beneficial activities could enhance benefits and reduce side effects.