Investigation to Understand and Optimize Psilocybin
An Investigation of Strategies to Understand and Optimize the Antidepressant Effects of Psilocybin (The OPTIMIZE Study)
Charles Raison
141 participants
May 13, 2025
INTERVENTIONAL
Conditions
Summary
This study will examine the effects of a single dose of psilocybin, administered with psychological support, on symptoms of depression. It will also assess whether different post-dosing interventions, including a non-invasive technique called transcutaneous auricular Vagus Nerve Stimulation (taVNS), influence various psychological and behavioral outcomes. In addition, the study will explore objective measures of real-world social behavior and identify early behavioral responses that may be associated with long-term treatment outcomes.
Eligibility
Inclusion Criteria2
- Current diagnosis of Major Depressive Disorder (MDD), with a depressive episode lasting ≥ 60 consecutive days at the time of screening, as confirmed by structured clinical interview
- Medically healthy, as determined by the screening physician, with no significant medical conditions that would interfere with participation or affect the safety of the subject.
Exclusion Criteria8
- History or presence of any psychiatric or medical condition that, in the opinion of the investigator, could pose a safety risk, interfere with participation, or confound study results (e.g., bipolar disorder, psychosis, seizure disorder, or cardiovascular disease).
- Known family history of a psychotic disorder (e.g., schizophrenia or schizoaffective disorder) in a first-degree relative (biological parent, full sibling, or child).
- Current active suicidal ideation with a specific plan within the prior 2 weeks, as assessed via clinical interview and validated instrument (e.g., C-SSRS).
- Suicide attempt within the prior 6 months, regardless of intent or lethality.
- Current diagnosis of a substance use disorder
- Abnormal ECG at screening that may increase risk during participation (e.g., prolonged QTc, arrhythmias, or other clinically significant findings as determined by the study physician).
- Unwilling or unable to discontinue prescription psychotropic medications (e.g., antidepressants, antipsychotics, anxiolytics, lithium, anticonvulsants, or mood stabilizers) for the duration of study participation, including any necessary washout period as determined by the investigator.
- Any condition, finding, or behavior (including suspected deception or noncompliance) that, in the opinion of the investigator, renders the participant unsuitable for the study or likely to interfere with the integrity of the data or safety of the subject.
Interventions
The psilocybin used in this study is synthesized under Good Manufacturing Practice (GMP) guidelines and is provided in a capsule containing 25 mg of synthetic psilocybin.
Participants will be provided with a taVNS device and trained on its use. The device delivers gentle stimulation to the left ear.
Participants will be provided with a taVNS device and trained on its use. The device delivers gentle stimulation to the left ear. In the sham condition, the device will simulate the sensations of active taVNS without delivering therapeutic stimulation.
Locations(1)
View Full Details on ClinicalTrials.gov
For the most up-to-date information, visit the official listing.
NCT06512194