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Psilocybin for treatment-resistant depression: fMRI-measured brain mechanisms.

Robin Carhart-Harris, Leor Roseman, Mark Bolstridge, Lysia Demetriou, J Nienke Pannekoek, Matthew B. Wall, Mark Tanner, Mendel Kaelen, John Mcgonigle, Kevin Murphy, Robert Leech, Helen Valerie Curran, David Nutt

Sci Rep October 13, 2017 DOI: 10.1038/s41598-017-13282-7 (opens in new tab)

Study at a glance

AI-extracted from the abstract
Characteristics Observational cohort Peer reviewed
Sample size 19
Population Patients with treatment-resistant depression
Intervention Psilocybin
Duration 1-week and 5-week follow-up
Topics Neuroplasticity Psilocybin Depression
Keywords Psychedelic Depression treatment Antidepressant Mental health therapy Brain connectivity Neural networks Brain function Neuroimaging FMRI Functional MRI
Citations 590
Key findings Psilocybin treatment decreased amygdala cerebral blood flow and increased default-mode network connectivity, with specific connectivity changes predicting clinical response at five weeks.

Abstract

Psilocybin with psychological support is showing promise as a treatment model in psychiatry but its therapeutic mechanisms are poorly understood. Here, cerebral blood flow (CBF) and blood oxygen-level dependent (BOLD) resting-state functional connectivity (RSFC) were measured with functional magnetic resonance imaging (fMRI) before and after treatment with psilocybin (serotonin agonist) for treatment-resistant depression (TRD). Quality pre and post treatment fMRI data were collected from 16 of 19 patients. Decreased depressive symptoms were observed in all 19 patients at 1-week post-treatment and 47% met criteria for response at 5 weeks. Whole-brain analyses revealed post-treatment decreases in CBF in the temporal cortex, including the amygdala. Decreased amygdala CBF correlated with reduced depressive symptoms. Focusing on a priori selected circuitry for RSFC analyses, increased RSFC was observed within the default-mode network (DMN) post-treatment. Increased ventromedial prefrontal cortex-bilateral inferior lateral parietal cortex RSFC was predictive of treatment response at 5-weeks, as was decreased parahippocampal-prefrontal cortex RSFC. These data fill an important knowledge gap regarding the post-treatment brain effects of psilocybin, and are the first in depressed patients. The post-treatment brain changes are different to previously observed acute effects of psilocybin and other 'psychedelics' yet were related to clinical outcomes. A 'reset' therapeutic mechanism is proposed.

In the evidence

This study is part of the evidence base for 2 syntheses in the library. Here is how each one recorded it.

  • Psilocybin treatment decreased amygdala cerebral blood flow and increased default-mode network connectivity, with specific connectivity changes predicting clinical response at five weeks; 47% met criteria for response at 5 weeks.

    Synthesized

  • Psilocybin treatment decreased amygdala cerebral blood flow and increased default-mode network connectivity, with specific connectivity changes predicting clinical response at five weeks.

    Synthesized

Comparable studies

Other observational and cohort studies on psilocybin for depression, most cited first.

Study Year Design Participants
Psilocybin with psychological support improves emotional face recognition in treatment-resistant depression Patients with treatment-resistant depression and healthy controls 2017 Observational cohort n = 33
More Realistic Forecasting of Future Life Events After Psilocybin for Treatment-Resistant Depression Patients with treatment-resistant depression (TRD) 2018 Observational cohort n = 15
Natural speech algorithm applied to baseline interview data can predict which patients will respond to psilocybin for treatment-resistant depression. 17 patients with treatment-resistant depression and 18 untreated age-matched healthy... 2018 Observational cohort with machine learning classification n = 35
Brain dynamics predictive of response to psilocybin for treatment-resistant depression. Responders and non-responders to psilocybin therapy for depression 2024 Observational cohort
Predicting the outcome of psilocybin treatment for depression from baseline fMRI functional connectivity. Patients with treatment-resistant depression or moderate-to-severe major depression 2024 Observational cohort n = 38

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