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.
Research Square
December 28, 2023
Joshua M. Poulin, Gregory E. Bigford, Krista L. Lanctôt et al.
1 citation
About one third of people with depression do not fully respond to standard treatments, and psilocybin may offer a rapid-acting alternative. This registered trial will randomize 36 adults with major depressive or persistent depressive disorder to receive either 25 mg psilocybin or an active placebo (100 mg niacin), then cross over three weeks later so that all participants receive psilocybin. Using serial neuroimaging, the study will test whether psilocybin acutely alters cerebral blood flow and functional brain activity in mood-related networks compared to placebo, and whether those changes persist subacutely. Clinical scales and serum biomarkers will also be collected to explore relationships with treatment response.
CNS Drugs
July 1, 2026
Omer A. Syed, Valentyn Sobolenko, Sean M. Nestor et al.
Most demographic and clinical variables do not reliably predict who will benefit from ketamine or esketamine for treatment-resistant depression, though a few promising factors—such as early response to treatment and a family history of substance use disorders—warrant further study. This systematic review synthesized 122 studies involving 12,674 participants, finding that the majority of 77 examined predictor variables showed no association with antidepressant outcomes. The review included both unipolar and bipolar treatment-resistant depression, with most studies using intravenous ketamine at a fixed 0.5 mg/kg dose.
Neuroscience & Biobehavioral Reviews
January 24, 2026
Omer A. Syed, Benjamin Tsang, Sean M. Nestor et al.
Psilocybin-assisted therapy (PAT) shows a large and significant antidepressant effect in treating major depressive disorder, based on a meta-analysis of seven randomized controlled trials involving 522 participants. Larger effects were associated with bodyweight-adjusted dosing, longer preparation, dosing, and integration sessions, and non-manualized psychotherapy, though subgroup differences were not statistically significant. The review provides preliminary guidance for clinicians designing PAT protocols.