Frontiers in Psychiatry
February 10, 2023
Muhammad Ishrat Husain, Nicole Ledwos, Elise Fellows et al.
47 citations
A narrative review examined the neurobiological mechanisms that may explain the rapid antidepressant effects of serotonergic psychedelics such as psilocybin, LSD, and ayahuasca. The drugs act as agonists or partial agonists at serotonin 5HT2A receptors, and their rapid effects may involve downregulation of these receptors. They also influence brain-derived neurotrophic factor and immune responses. Neuroimaging studies suggest that psychedelics may disrupt the default mode network, a brain system involved in self-referential thinking that is overactive in major depressive disorder. The review concludes that multiple competing theories are being investigated and more research is needed to identify the most robust evidence.
BJPsych Open
July 1, 2023
Muhammad Ishrat Husain, Nicole Ledwos, Elise Fellows et al.
41 citations
A proof-of-concept randomized controlled trial will test whether combining the psychedelic psilocybin with risperidone, a drug that blocks the serotonin 2A receptor, can block psilocybin's psychedelic effects while preserving its antidepressant action in adults with treatment-resistant depression. Sixty participants will be randomly assigned to receive psilocybin plus risperidone, psilocybin alone, or placebo plus risperidone, all with 12 hours of manualized psychotherapy. Feasibility and tolerability will be assessed through recruitment, retention, and adverse events. If successful, this approach could make psilocybin therapy more acceptable and accessible by eliminating the need for a psychedelic experience and continuous monitoring.
Journal of Clinical Psychopharmacology
Nicole Ledwos, Joshua D. Rosenblat, Daniel M. Blumberger et al.
16 citations
A critical appraisal of clinical trials on serotonergic psychedelics for major depressive disorder and end-of-life distress finds that current evidence is low-level due to methodological limitations. Small randomized trials of psilocybin combined with psychotherapy showed superiority to waitlist controls and comparable efficacy to an active comparator, with similar preliminary positive effects for single-dose ayahuasca in treatment-resistant depression and lysergic acid diethylamide for end-of-life distress. Adverse events were mild and transient. However, small homogenous samples, expectancy bias, functional unblinding, and lack of standardized psychotherapy limit all studies. Psychedelics should remain experimental interventions used within clinical trials.
Journal of Affective Disorders
July 18, 2025
Mary E. Kittur, Mingyao Liu, Brett D. M. Jones et al.
12 citations
Psilocybin therapy shows promise for rapid and lasting clinical benefits when paired with psychological support, but the field lacks standardized therapeutic guidelines. A systematic review of 22 recent trials across conditions like depression, substance use, and obsessive-compulsive disorders found broad consistency in the structure of therapy sessions—before, during, and after psilocybin administration. However, trials varied widely in therapeutic intensity, diagnostic adaptations, and use of evidence-based psychotherapies. Fewer than half reported standardization measures such as manualized procedures, specific training, or adherence monitoring. These gaps undermine replicability and generalizability, and until support protocols are clearly defined, mechanistic understanding and clinical adoption will remain limited.
Journal of Psychoactive Drugs
August 24, 2023
Stanley Wong, An Yi Yu, Nicholas Fabiano et al.
11 citations
Interest in psychedelic therapies for mental and substance use disorders has grown, but evidence for non-psilocybin serotonergic psychedelics remains limited. A scoping review of mescaline, ibogaine, ayahuasca, DMT, and LSD identified 77 studies: 43 on LSD, 24 on ayahuasca, and 5 each on DMT, ibogaine, and mescaline. Reported benefits included improved mood, anxiety, insight, reduced substance use, better relationships, and fewer vegetative symptoms. Adverse effects were psychological, neurological, physical, and gastrointestinal; serious events like homicide and suicide appeared in LSD studies. The review concludes there is only low-level evidence supporting the safety and efficacy of these substances for mental and substance use disorders.
Therapeutic Advances in Psychopharmacology
September 1, 2025
Stanley Wong, Gray Meckling, Nicholas Fabiano et al.
6 citations
A systematic review and meta-analysis of nine randomized controlled trials involving 593 adults with psychiatric diagnoses found that psilocybin therapy led to a small but significant decrease in suicidal ideation compared to control conditions. No studies reported suicide attempts or deaths. The analysis showed low heterogeneity and no publication bias, though two studies had a high risk of bias. Current evidence is limited by small sample sizes, insufficient follow-up data, and inadequate assessment of blinding.
Ther Adv Psychopharmacol
October 16, 2025
Stanley Wong, Brett D. M. Jones, Mathura T. Thiyagarajah et al.
3 citations
A review of nine small clinical trials found that ayahuasca and psilocybin, when used to treat major depressive disorder and treatment-resistant depression, are associated with changes in several biological markers. These include increased serum brain-derived neurotrophic factor, decreased serum C-reactive protein, altered amygdala activation, and changes in functional connectivity between brain regions such as the ventromedial prefrontal cortex, anterior cingulate cortex, and posterior cingulate cortex. These associations suggest potential mechanisms of clinical response, but larger, longer-term studies are needed to confirm these findings.
Journal of Affective Disorders
January 23, 2026
Reinhard Janssen-Aguilar, Jithin Joseph, Huda Al-Shamali et al.
In a retrospective chart review of 209 adults with treatment-resistant depression treated with intravenous ketamine, depressive and anxiety symptoms improved significantly over four or six infusions, but the improvements were modest and highly variable across individuals. Anxiety symptoms improved more slowly and less robustly than depressive symptoms. End-of-treatment response and remission rates were numerically higher after six infusions than after four, but the difference was not statistically significant. Four distinct patterns of symptom change emerged for both depression and anxiety, highlighting the heterogeneity of treatment response. Durability after six infusions could not be assessed because follow-up data were available only for the four-infusion group.
Biological Psychiatry
April 9, 2025
Mary E. Kittur, L. Martínez, Brett D. M. Jones et al.
No Summary
Journal of Pain Research
January 1, 2025
Darren K Cheng, Robert Simpson, Rahim Moineddin et al.
A virtual Sahaj Samadhi Meditation program did not significantly outperform an active control (Health Enhancement Program) in reducing depressive symptoms among people with chronic pain and moderate depression. Within the meditation group, depressive symptoms decreased by an average of 3.97 points on the PHQ-9 at 12 weeks and 4.96 points at 24 weeks, both exceeding the minimal clinically important difference, while the control group showed no significant change. The trial enrolled 108 participants, with 89 randomized. The findings suggest potential benefits of the meditation program, but larger trials under non-pandemic conditions are needed to confirm effectiveness.