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Decreased brain modularity after psilocybin therapy for depression.

Richard E. Daws, Christopher Timmerman, Bruna Giribaldi, James D. Sexton, Matthew B. Wall, David Erritzøe, Leor Roseman, David Nutt, Robin Carhart-Harris

Research Square May 20, 2021 preprint DOI: 10.21203/rs.3.rs-513323/v1 (opens in new tab)

Study at a glance

AI-extracted from the abstract
Characteristics Open-label trial and double-blind randomized controlled trial
Sample size 59
Population Adult patients with treatment-resistant depression or major depressive disorder
Interventions Psilocybin Escitalopram
Dose 10mg and 25mg; 2 x 25mg; 2 x 1mg; 10-20mg
Duration 1 week and 6 months follow-up in study 1; 6 weeks in study 2
Topics Psilocybin Depression
Keywords Modularity biology Depression economics Psychotherapist Hallucinogen Keynesian economics
Citations 11
Registration NCT03429075
Key findings Psilocybin therapy's antidepressant effects are associated with decreased brain network modularity post-treatment.

Abstract

Abstract Importance Psilocybin therapy shows antidepressant potential; our data link its antidepressant effects to decreased brain network modularity post-treatment.

Objective: To assess the sub-acute impact of psilocybin on brain activity in patients with depression.

Design: Pre vs post-treatment resting-state functional MRI (fMRI) was recorded in two trials: 1) Open-label treatment-resistant depression (TRD) trial with baseline vs 1 day post-treatment fMRI (April-2015 to April-2016); 2) Two-arm double-blind RCT in major depressive disorder (MDD), fMRI baseline vs 3 week after psilocybin-therapy or 6 weeks of daily escitalopram (January-2019 to March-2020).

Setting: Study visits occurred at the NIHR Imperial Clinical Research Facility.Participants Adult male and female patients with TRD or MDD. Intervention(s) (for clinical trials) or Exposure(s) (for observational studies)Study 1: Two oral doses of psilocybin (10mg and 25mg, fixed order, 7 days apart). fMRI was recorded at baseline and one day after the 25mg dose. Study 2: either: 2 x 25mg oral psilocybin, 3 weeks apart, plus 6 weeks of daily placebo (‘psilocybin-arm’), or 2 x 1mg oral psilocybin, 3 weeks apart, plus 6 weeks of daily escitalopram [10-20mg] (‘escitalopram-arm’). fMRI was recorded at baseline and 3 weeks after the 2nd psilocybin dose, which was the final day of the 6-week daily capsule ingestion. Main Outcome(s) and Measure(s) Beck Depression Inventory and fMRI network modularity.

Results: Study 1: In 16 adults (mean age [SD], 42.8 [10.1] years, 4 [25%] female), psilocybin therapy was associated with markedly decreased BDI scores at 1 week (mean difference, -21; 95% CI=[-27.3, -14.7], P<.001) and 6 months (mean difference, -14.19; 95% CI=[-21.3, -7.1], P<.001). Decreased network modularity at one day post-treatment correlated with treatment response at 6 months (Pearson, 0.64; P=.01). Study 2: In 43 adults (42.7 [10.5] years, 14 [33%] female), antidepressant effects favoured the psilocybin-arm at 2 (mean difference, -8.76; 95% CI=[-13.6, -3.9], P=.002) and 6 weeks (mean difference, -8.78; 95% CI=[-15.6, -2.0], P=.01). Specific to the psilocybin-arm, improvements at the 6-week primary endpoint correlated with decreased network modularity (Pearson, -0.42, P=.025). Conclusions and Relevance Consistent efficacy-related functional brain changes correlating with robust and reliable antidepressant effects across two studies suggest a candidate antidepressant mechanism for psilocybin therapy: decreased brain network modularity. Trial registration ClinicalTrials.gov identifier: NCT03429075

Comparable studies

Other randomized controlled trials on psilocybin for depression, most cited first.

Study Year Design Participants
Psilocybin produces substantial and sustained decreases in depression and anxiety in patients with life-threatening cancer: A randomized double-blind trial Cancer patients with life-threatening diagnoses and symptoms of depression and/or anxiety 2016 Randomized controlled trial n = 51
Rapid and sustained symptom reduction following psilocybin treatment for anxiety and depression in patients with life-threatening cancer: a randomized controlled trial Patients with cancer-related anxiety and depression 2016 Double-blind, placebo-controlled, crossover trial n = 29
Trial of Psilocybin versus Escitalopram for Depression Selected group of patients with depression 2021 Randomized controlled trial
Effects of Psilocybin-Assisted Therapy on Major Depressive Disorder Adults aged 21 to 75 years with major depressive disorder, not currently using... 2020 Randomized controlled trial n = 24
Single-Dose Psilocybin for a Treatment-Resistant Episode of Major Depression. Adults with treatment-resistant depression 2022 Phase 2 double-blind randomized controlled trial n = 233

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