The New England journal of medicine
November 3, 2022
Guy M Goodwin, Scott T Aaronson, Oscar Alvarez et al.
1,095 citations
A single 25 mg dose of psilocybin, but not 10 mg, reduced depression scores more than a 1 mg control dose over three weeks in adults with treatment-resistant depression. In this phase 2 trial, 233 participants were randomly assigned to 25 mg, 10 mg, or 1 mg of synthetic psilocybin with psychological support. The 25 mg group showed an average 12-point drop on the MADRS depression scale versus a 5.4-point drop in the 1 mg group, a significant difference. The 10 mg group did not differ significantly from control. Response and remission rates at three weeks supported the primary result, but sustained response at 12 weeks was not significantly different.
Irish Journal of Psychological Medicine
September 23, 2019
John R. Kelly, Annie Baker, Mona Babiker et al.
22 citations
A growing body of preliminary clinical research indicates that psilocybin, a compound found in hallucinogenic fungi, combined with psychological support can improve mood, reduce anxiety, and enhance quality of life. An open-label study showed marked reductions in depression symptoms among participants with treatment-resistant depression. The underlying neurobiological changes include altered brain connectivity and activity in the amygdala and default mode network, as well as increased synaptogenesis and neural plasticity. A randomized, double-blind trial has recently launched across Europe and North America, including a center in Ireland, to further test psilocybin's efficacy for treatment-resistant depression.
Irish Journal of Psychological Medicine
August 19, 2020
John R. Kelly, Matthew Crockett, Laith Alexander et al.
16 citations
The medium- to long-term mental health consequences of COVID-19 are predicted to increase, requiring multidisciplinary strategies. Psilocybin therapy shows promise as a transdiagnostic treatment for disorders with maladaptive habitual patterns, such as depression, addiction, and obsessive compulsive disorder. The COMPASS Pathways phase 2b double-blind trial is testing psilocybin therapy in antidepressant-free treatment-resistant depression (TRD) to determine safety, efficacy, and optimal dose. Results from the Imperial College London Psilodep-RCT comparing psilocybin therapy to the SSRI escitalopram will soon be published. The efficacy and safety of psilocybin therapy with SSRIs in TRD is not yet known; a COMPASS study in Dublin will address this. Psilocybin therapy may play an important role in post-COVID-19 psychiatry, though it is at an early clinical stage.
The international journal of neuropsychopharmacology
June 2, 2026
John R Kelly, Christopher Sheridan, Patricia Iusan et al.
Classical serotonergic psychedelics like psilocybin show emerging evidence of therapeutic potential across depression, anxiety, and substance use disorders, with indications of transdiagnostic efficacy. Early-phase studies yielded encouraging results, but recent larger-scale phase 3 trials for treatment-resistant depression have shown more modest effects. No regulatory approvals from the U.S. FDA or EMA exist, though a few countries permit psychedelic therapies in regulated clinical settings. The long-term trajectory and real-world impact within public health systems remain uncertain. This paper examines challenges for integrating psychedelic therapies into Ireland's public healthcare system, covering regulatory approval, Health Technology Assessment, service implementation, workforce capacity, and evaluation of long-term patient outcomes.