Psilocybin for Treatment-Resistant Depression in Autism

We propose a first-of-its-kind open-label clinical trial to investigate the feasibility, tolerability, and safety of administering psilocybin in autistic adults with treatment-resistant depression (TRD). In this study, 20 participants (intellectually able and fluent-speech adults) with autism and co-occurring TRD will receive around 20 hours of manualized psychotherapy that has previously been used with psilocybin (Agin-Liebes et al., 2020). They will also receive psilocybin at 2 different time points, firstly a safety dose of 10mg, followed by a treatment dose of 25mg. This study design is in accordance with previous studies investigating the use of psilocybin with psilocybin-assisted therapy (PAT) to treat TRD (Carhart-Harris et al., 2016, 2018)

NCT Number	NCT06731621
Lead Sponsor	Centre for Addiction and Mental Health
Conditions	Treatment Resistant Depression, Autism Spectrum Disorder
Enrollment	20 participants
Start Date	2024-11-01
Primary Completion	2026-12 (estimated)
Study Completion	2026-12 (estimated)
Updated on ClinicalTrials.gov	2026-08-06