Mindfulness‑assisted Psilocybin Therapy

An Exploratory Study of Feasibility, Efficacy, and Mechanisms of Mindfulness-Assisted Psychedelic Therapy

PHASE2 · University of Southern California · NCT06233344

This trial will test whether adding eight weeks of guided mindfulness classes to a single supervised dose of psilocybin improves mental health effects in healthy adults aged 25 and older.

Quick facts

PhasePHASE2
Study typeInterventional
Enrollment40 (estimated)
Ages25 Years and up
SexAll
SponsorUniversity of Southern California (other)
Locations1 site (Los Angeles, California)
Trial IDNCT06233344 on ClinicalTrials.gov

What this trial studies

This Phase 2 pilot randomizes 40 eligible healthy adults to one of two arms: a single supervised psilocybin session plus eight weeks of weekly mindfulness training or a single supervised psilocybin session alone. Participants complete baseline and post‑treatment assessments including questionnaires, computerized cognitive tests, and EEG, with follow‑up surveys at 8 weeks and 1 year. The primary feasibility outcome is retention at the 8‑week follow‑up, with secondary outcomes examining changes in clinical and cognitive measures. Participants must have no prior formal mindfulness training or prior classic psychedelic use and follow pre‑session medication and substance restrictions.

Who should consider this trial

Good fit: Healthy adults aged 25 or older with little or no prior meditation experience and no previous classic psychedelic use are the intended participants.

Not a fit: People under 25, those with prior psychedelic experience or formal mindfulness training, or individuals seeking treatment for active psychiatric disorders (if excluded) may not benefit from joining this pilot.

Why it matters

Potential benefit: If successful, combining formal mindfulness training with psilocybin could enhance and prolong beneficial mental‑health effects compared with psilocybin alone.

How similar studies have performed: Previous trials of psilocybin alone have shown promising mental health effects, but combining psilocybin with a formal eight‑week mindfulness program is novel and has only limited prior data.

Eligibility criteria

Show full inclusion / exclusion criteria
Eligible participants will be:

* Adults of any race, ethnicity, or gender who are age 25 years or older
* Have not had formal mindfulness training
* Have not previously used classic psychedelics
* Agree to consume approximately the same amount of caffeine-containing beverage (e.g., coffee, tea) that he/she consumes on a usual morning, before arriving at the research unit on the morning of the drug session day. If the participant does not routinely consume caffeinated beverages, he/she must agree not to do so on the session day.
* Agree to refrain from using any psychoactive drugs, including alcoholic beverages and nicotine, within 24 hours of each drug administration. The exception is caffeine.
* Agree not to take any PRN medications on the mornings of drug sessions
* Agree not to take sildenafil (Viagra®), tadalafil, or similar medications within 72 hours of psilocybin administration.
* Agree that for one week before the drug session, he/she will refrain from taking any nonprescription medication, nutritional supplement, or herbal supplement except when approved by the study investigators. Exceptions will be evaluated by the study investigators and will include acetaminophen, non-steroidal anti-inflammatory drugs, and common doses of vitamins and minerals.

Participants will be excluded if they present with any of the following:

* Prior exposure to formal mindfulness or meditation training
* Previous use of psilocybin or other psychedelic drugs (LSD, mescaline, DMT/ayahuasca, 5-methoxy-DMT)
* Current use of tricyclic antidepressants, serotonin reuptake inhibitors, antipsychotics, atypical antipsychotics, monoamine oxidase inhibitors (MAOIs), mood stabilizers (lithium), buspirone, mirtazapine, trazodone, or other drugs that modulate the serotonin system. For individuals who have intermittent or PRN use of such medications, psilocybin sessions will not be conducted until at least 5 half-lives of the agent have elapsed after the last dose.
* Current use of St. John's Wort or 5-hydroxytryptophan
* Currently taking psychoactive prescription medication on a regular (e.g., daily) basis
* Current or lifetime history of schizophrenia, other psychotic disorders, or bipolar I or II disorder; or a first or second degree relative with one of these disorders
* Current or recent past (within the past 5 years) history of alcohol or drug dependence (other than caffeine or nicotine) or major depressive episode
* Current or recent suicidal ideation (within the past month) or behavior (within the past 6 months), as assessed by a response of "yes" to any of questions in the "Suicidal Ideation" or "Suicidal Behavior" on the C-SSRS at the eligibility screen or baseline session
* Current (past two weeks) self-reported risky alcohol use (\>7 drinks/week for women or \>14 drinks/week for men)
* Current obsessive-compulsive disorder, dysthymic disorder, panic disorder, dissociative disorder, anorexia nervosa, or bulimia nervosa
* Has a psychiatric condition judged to be incompatible with establishment of rapport or safe exposure to psilocybin
* Self-reported use of or positive urine drug screen for amphetamines/methamphetamine, opioids, barbiturates, methadone, cocaine, or PCP at the eligibility screen visit or the psilocybin visit
* Positive breath alcohol test at the eligibility screen visit or the psilocybin visit (BrAC \> 0.01)
* Current pregnancy, planned pregnancy in the next 6 months (at phone screen or eligibility screen), positive urine pregnancy test (for participants of childbearing potential) at the eligibility screen or the psilocybin session, or current breastfeeding
* Unwilling to use a medically-accepted highly effective form of birth control (such as hormonal implants, intrauterine devices (IUDs), hormonal birth control pills, surgical sterility, or other methods deemed highly effective (\<1% failure rate) by the study physician) during the study (applies to male participants as well as female participants of childbearing potential)
* Cardiovascular conditions: coronary artery disease, stroke, angina, uncontrolled hypertension, a clinically significant ECG abnormality (e.g., atrial fibrillation, QTc greater than 450 msec), artificial heart valve, or TIA in the past year
* Epilepsy with history of seizures
* Current unstable medical condition (including uncontrolled or poorly controlled hypertension - resting blood pressure greater than 140 (systolic) or 90 (diastolic) mmHg at the eligibility screening will be reviewed by the study physician and participants with stable hypertension will be asked to follow-up with their primary care physician to initiate appropriate hypertensive treatment prior to proceeding)
* Diabetes (type 1 or 2) with insulin dependence; if taking oral hypoglycemic agent, then no history of hypoglycemia
* Any other medical condition that may be incompatible with safe exposure to psilocybin
* Inability to speak English
* Inability to provide informed consent

Where this trial is running

Los Angeles, California

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.

View on ClinicalTrials.gov →

Conditions: Mental Health, Psychedelic therapy, Psilocybin, Mindfulness

Last reviewed 2026-05-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.