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DepressionPhase 2OPTIMIZENCT06512194

Investigation to Understand and Optimize Psilocybin

A Phase 2 study testing Psilocybin and Transcutaneous Auricular Vagus Nerve Stimulation (taVNS) in people with Depression, run by Charles Raison at 1 site in United States.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
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Trial 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… Read more about this study

Who is it for?
Ages 18 to 70 years
Conditions the study is for
Depression
What is being tested?
Psilocybin and Transcutaneous Auricular Vagus Nerve Stimulation (taVNS)
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
141 participants
Where
1 siteUnited States
Study dates
13 May 2025to May 2029
Phase
Phase 2
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 70 years
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • 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.

Who cannot join

  • 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.

Trial locations and contacts

1 site in 1 country. Contact the study team or a site near you to ask about taking part.

Program Manager contact

(970) 855-7374

bhic@vailhealth.org

United States1 site, 1 recruiting
  • Vail Health Behavioral Health

    Edwards, Colorado, 81632

    Program Manager, (970) 855-7374, bhic@vailhealth.org

    Recruiting

Other trials in United States

About this study

Official title: An Investigation of Strategies to Understand and Optimize the Antidepressant Effects of Psilocybin (The OPTIMIZE Study)

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.

Read the detailed description

One hundred forty-one adults ages 18 to 70 experiencing a major depressive episode of at least 60 days duration of moderate or greater severity at screening will be enrolled to obtain evaluable data on approximately 120 participants.

All participants will receive a single 25 mg dose of psilocybin using a "set and setting" therapeutic approach that will include 1) several hours of preparatory sessions prior to dosing and 2) the presence of two facilitators throughout the dosing session; and 3) several post dosing integration sessions with a facilitator.

Following the psilocybin dosing session, participants will be randomized to 1) taVNS (7 days of twice daily taVNS), 2) sham taVNS (7 days of twice daily sham taVNS), or 3) no taVNS.

Both taVNS and sham sessions will include guided prompts encouraging participants to reflect on key aspects of their psychedelic experience, accompanied by music previously used during the psilocybin dosing session.

Participants will complete assessments at multiple time points to evaluate depression, anxiety, well-being, functional disability, quality of life, social behavior, suicidal ideation, and adverse events before and after psilocybin dosing.

Conditions
Depression
Being tested
Psilocybin, Transcutaneous Auricular Vagus Nerve Stimulation (taVNS), Sham taVNS
Keywords
depression, psilocybin, psychedelics, transcutaneous auricular vagus nerve stimulation, depressive symptoms, well-being, adverse events, ecological momentary assessment, electronically activated recorder, dynamical complexity assessment
Medical subject headings
Depression

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • PsilocybinDrug

    Also called Psilocybine, Psilocibin, Usona Institute Psilocybin

    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.

  • Transcutaneous Auricular Vagus Nerve Stimulation (taVNS)Device

    Also called taVNS

    Participants will be provided with a taVNS device and trained on its use. The device delivers gentle stimulation to the left ear.

  • Sham taVNSDevice

    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.

Study groups in NCT06512194
Study groupRoleWhat they receive
Group 1: Psilocybin + taVNSExperimentalParticipants in this arm will receive a single 25 mg dose of psilocybin, followed by twice-daily sessions of taVNS for 7 consecutive days. Each taVNS session will be paired with music and prompts related to the participant's psilocybin experience.
Receives: Drug: Psilocybin; Device: Transcutaneous Auricular Vagus Nerve Stimulation (taVNS)
Group 2: Psilocybin + Sham taVNSSham comparatorParticipants in this arm will receive a single 25 mg dose of psilocybin, followed by twice-daily sham taVNS sessions for 7 consecutive days. Each sham session will be paired with music and prompts related to the participant's psilocybin experience.
Receives: Drug: Psilocybin; Device: Sham taVNS
Group 3: Psilocybin + No taVNSActive comparatorParticipants in this arm will receive a single 25 mg dose of psilocybin, followed by no additional intervention. They will receive the standard psychological support related to their psilocybin experience, but no taVNS or sham device will be used.
Receives: Drug: Psilocybin

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Montgomery-Åsberg Depression Rating Scale (MADRS) score

    The MADRS is a 10-item depression rating scale that includes questions on the following symptoms: 1. Reported sadness, 2. Apparent sadness, 3. Inner tension, 4. Reduced sleep, 5. Reduced appetite, 6. Concentration difficulties, 7. Lassitude, 8. Inability to feel, 9. Pessimistic thoughts, and 10. Suicidal thoughts. Items are scored via a blinded clinical interview and rated to capture the patient's clinical state over the prior week. Each item yields a score of 0 to 6, and higher scores indicate more severe depression. The overall score ranges from 0 to 60. For this study, the structured MADRS interview will be used.

    Measured: Baseline 2, Week 8 Post-Psilocybin Dosing

  2. PROMIS Ability to Participate in Social Roles and Activities - Short Form 8a

    An 8-item validated measure assessing an individual's perceived ability to engage in social roles and activities, such as work, family responsibilities, and leisure. Participants rate each item on a 5-point Likert scale. Total score can range from 8 to 40 with higher scores indicating greater functional ability and social participation.

    Measured: Baseline 2, Week 8 Post-Dose

  3. Quality of Life Enjoyment and Satisfaction Questionnaire Short-Form (Q-LES-Q) score

    The Short Form version (Q-LES-Q-SF) will be used in this trial. The measure contains 16 items that assess quality of life. A total score is derived from summing the first 14 items on the scale, with the last 2 items serving as stand-alone queries. Total score can range from 14 to 70 with higher scores indicating better quality of life.

    Measured: Baseline 2, Week 8 Post-Dose

Secondary outcomes (11)
  1. Electronically Activated Recorder (EAR)

    The EAR is a naturalistic observation method that uses an audio recording app worn by subjects to silently and unobtrusively record short samples of ambient sounds while subjects go about their daily lives. These recordings can then be transcribed for subjects' natural daily speech, as well as coded for a wide range of aspects of subjects' objectively assessed locations, activities, conversations, social environments, and other behaviors. In the present study, the EAR allows us to measure how subjects' daily behaviors, activities and social interactions change over the course of the study.

    Measured: Up to 55 days

  2. Voicediary

    Voicediaries will be collected via the Fabla Voicediary App. The app will collect brief speech samples from subjects' talking about (a) the events of their days and (b) retrospective reflections on their experience of psilocybin (after dosing).

    Measured: Up to 35 days

  3. Ecological Momentary Assessment (EMA)

    EMA will be conducted via the Fabla Voicediary app. The app will send notifications to subjects' smartphones for assessments three times per day. Each item on the assessments will include 2 slider-type items assessing valence and arousal, 3 free response items assessing current context, 2 items assessing connectedness, 1 item assessing sense of meaning, and 2 collaboratively developed items that are personalized to the subject. In addition, one end-of-day assessment will also include 1 item about hours of sleep the previous night, 1 item about substance use in the past 24 hours, and 1 item asking whether subjects have had conversations about their upcoming (during pre-dosing) or past (during post-dosing) psilocybin experiences, and with whom.

    Measured: Up to 35 days

  4. Challenging Experiences Questionnaire (CEQ) score

    The CEQ is a 26-item questionnaire that consists of seven factors of challenging experience with psilocybin mushrooms: fear, grief, feeling of losing your sanity (insanity), feel as though you are dying (death), feelings of isolation, physiological distress, and paranoia. The CEQ uses a 6-point response scale [0: None/not at all, 1: So slight cannot decide, 2: Slight, 3: Moderate, 4: Strong; 5: Extreme (more than ever before in my life)] to indicate the degree to which a participant experiences each of a series of subjective effects during their psilocybin session. Total CEQ score is expressed as the percentage of the total possible ratings on the scale. Total score can range from 0-100% with higher scores indicating a greater challenging experience.

    Measured: Day 1 Post-Dose, Week 8 Post-Dose

  5. Warwick-Edinburgh Mental Wellbeing Scale (WEMWBS) score

    The WEMWBS has 14 questions scored using a five-point Likert scale. The items are all worded positively and cover both feeling and functioning aspects of mental wellbeing. Items on the questionnaire are rated on a 5-point scale, where 1= "None of the time", 2= "rarely", 3= "some of the time", 4= "often", 5= "all the time". The scale is scored by summing the response to each item. The minimum scale score is 14 and the maximum is 70. Scores reflect feelings and thoughts in the two weeks prior to answering the questionnaire with higher scores indicating better well-being.

    Measured: Baseline 1, Baseline 2, Week 2 Post-Dose, Week 4 Post-Dose, Week 8 Post-Dose

  6. Psychedelic Assisted Therapy Adverse Events (PATAE)

    The PATAE was developed to assess pre-dosing and post-acute dosing adverse events that may occur during psychedelic-assisted therapy due to the pharmacologic and psychotherapeutic components, as well as their interaction. The PATAE consists of 54 items that assess across 7 domains: sociocultural, psychospiritual, interpersonal, behavioral, psychotherapy-related, and perceptual.

    Measured: Baseline 1, Baseline 2, Day 1 Post-Dose, Week 1 Post-Dose, Week 2 Post-Dose, Week 4 Post-Dose, Week 8 Post-Dose

  7. 30-item Mystical Experiences Questionnaire (MEQ30) score

    The MEQ30 is a 30-item self-report measure developed to assess the effects of classic psychedelics in laboratory studies. It covers the major dimensions of the classic mystical experience: unity, transcendence, noetic quality, sacredness, positive mood, and ineffability/paradoxicality. The MEQ has 4 sub scales: 1) transcendence, 2) positive mood, 3) ineffability, and 4) mystical. The total possible range for each sub scale and total score is 0-100% with higher percentages indicating a larger mystical experience. Typically, a complete mystical experience is defined as scoring 60% or more on all four MEQ30 sub scales.

    Measured: Day 1 Post-Dose, Week 8 Post-Dose

  8. Emotional Breakthrough Inventory (EBI) score

    The EBI is a 6-item self-report scale that assesses the presence and severity of emotionally challenging/distressing experiences that occur during a psychedelic experience. The scale utilizes visual analog responses captured on a line anchored by "not at all" on one end and "very much so" on the other. Experiences queried include 1) facing emotionally difficult feelings that are usually pushed aside; 2) experiencing a resolution of a personal conflict/trauma; 3) being able to explore challenging emotions and memories; 4) having an emotional breakthrough; 5) getting a sense of closure on an emotional problem, and 6) achieving an emotional release followed by a sense of relief. The total possible score ranges from 0-100 with higher scores indicating a greater emotional breakthrough.

    Measured: Day 1 Post-Dose, Week 8 Post-Dose

  9. Psychological Insight Questionnaire (PIQ) score

    The PIQ is a 23-item instrument designed to query self-perceived attainment of insight during a psychedelic experience. It comprises two subscales: (a) Avoidance and Maladaptive Patterns Insights and Goals; and (b) Adaptive Patterns Insights. Sub scale and total scores range from 0 to 5 with a higher score indicating great psychological insight.

    Measured: Day 1 Post-Dose, Week 8 Post-Dose

  10. Ego Dissolution Inventory (EDI) score

    The EDI is an 8-item self-report scale designed to measure ego-dissolution. Each item is scored on a visual analogue scale from 0 to 100 with the following statements at the lower and upper end, respectively: "No, not more than usually" and "Yes, I experienced this completely/entirely." The total possible range of scores for the EDI is 0-100 with higher scores indicating a greater ego dissolution.

    Measured: Day 1 Post-Dose, Week 8 Post-Dose

  11. Awe Experiences Questionnaire - Short Form (AWE-SF) score

    The AWE-SF is a 12-item self-report scale that measures the state of awe. Each items is rated on a scale of 1 to 7, with 1 representing "Strongly Disagree" and 7 representing "Strongly Agree". The total possible range of scores for the AWE is 12-84 with higher scores indicating a greater awe.

    Measured: Day 1 Post-Dose, Week 8 Post-Dose

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted22 Jul 2024
  2. Study start13 May 2025
  3. Primary completionMay 2029 (estimated)
  4. Study completionMay 2029 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 2
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Model description
All subjects will receive a single 25 mg dose of psilocybin administered within a "set and setting" (SaS) framework of psychological support provided by trained clinicians. Post-dosing, subjects will be randomized to 1) taVNS, 2) sham taVNS, or 3) no taVNS.
Masking
Quadruple blind
Who is masked
Participant, Care provider, Investigator, Outcomes assessor
Enrolment
141 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT06512194
Sponsor's protocol ID
20243954
Acronym
OPTIMIZE
Status last verified
Aug 2026
First submitted
16 Jul 2024
Last updated
10 Aug 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
Yes
Individual data sharing
Yes: De-identified data including, but not limited to, demographics, questionnaires, and adverse events will be made available upon request.

Questions about this trial

What is this clinical trial studying?

A Phase 2 study testing Psilocybin and Transcutaneous Auricular Vagus Nerve Stimulation (taVNS) in people with Depression, run by Charles Raison at 1 site in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 2 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: looking for participants now, as of the sponsor's last update on 10 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Program Manager ((970) 855-7374, bhic@vailhealth.org), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Montgomery-Åsberg Depression Rating Scale (MADRS) score (time frame: Baseline 2, Week 8 Post-Psilocybin Dosing). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 10 Aug 2026.

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