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.
Journal of affective disorders
March 1, 2025
Guy M Goodwin, Scott T Aaronson, Oscar Alvarez et al.
35 citations
In treatment-resistant depression, a single dose of 25 mg of psilocybin produced stronger correlations between certain psychedelic experiences and depression improvement three weeks later than lower doses. The intensity of psychedelic effects was dose-related, but scores for different doses overlapped considerably. At the 25 mg dose, dimensions of oceanic boundlessness and visual restructuralization, along with emotional breakthrough, showed the strongest correlations with reduced depression scores. The study does not establish causation and requires replication. The overlap in experience intensity across doses suggests unblinding to dose is less likely. Correlations between psychedelic experience and outcome indicate specificity in psilocybin's mechanism of action.
Focus (American Psychiatric Publishing)
October 1, 2023
Farhan Fancy, Nelson B Rodrigues, Joshua D Di Vincenzo et al.
4 citations
Repeated intravenous ketamine infusions significantly reduced depression, suicidal thoughts, and anxiety in patients with treatment-resistant bipolar I/II depression, and improved functioning. In an observational study of 66 patients receiving four infusions over two weeks, depressive symptoms dropped by an average of 6.08 points on the QIDS-SR16 scale. Response rate was 35% and remission rate 20%. Hypomania occurred in only 4.5% of patients, with no mania or psychosis. The findings suggest real-world effectiveness and tolerability of IV ketamine for bipolar depression.
Trials
July 3, 2024
Joshua M Poulin, Gregory E Bigford, Krista L Lanctôt et al.
3 citations
A proposed randomized controlled trial will test whether a single 25 mg dose of psilocybin, compared to a placebo, acutely alters cerebral blood flow and functional brain activity in mood-regulating networks in people with major depressive disorder or persistent depressive disorder. Fifty participants from a mood disorders clinic will be randomly assigned to receive either psilocybin or a placebo, with the placebo group later crossing over to receive psilocybin. The study will use arterial spin labelling and blood oxygenation level-dependent functional MRI to measure brain changes intraday and at three weeks. Clinical outcomes will be tracked with the Montgomery-Åsberg Depression Rating Scale and other scales. The work aims to clarify psilocybin's neuroplastic mechanisms and identify early brain-based predictors of treatment response.
Journal of affective disorders
August 1, 2026
Guy M Goodwin, Scott T Aaronson, Oscar Alvarez et al.
2 citations
In people with treatment-resistant depression receiving 25 mg psilocybin with monitoring and support, the therapeutic alliance before dosing had only weak correlations with improvement in depression scores at three weeks. Stronger correlations were seen with the intensity of the psychedelic experience itself, particularly emotional breakthrough and visual restructuring. Path analysis suggested that therapeutic alliance helped facilitate the psychedelic experience, but it was the psychedelic experience—not the alliance—that had stronger direct effects on clinical outcomes. The alliance's direct effect on antidepressant response was limited or absent.