A Trial of the Fatty Acid Amide Hydrolase Inhibitor Palmitoylethanolamide in Bipolar Depression

August 10, 2026 updated by: Rodrigo Machado-Vieira, MD, PhD, MSc

A Randomized Controlled Trial of the Fatty Acid Amide Hydrolase Inhibitor Palmitoylethanolamide in Bipolar Depression

The purpose of this study is to o evaluate the antidepressant efficacy of the PEA in Bipolar Depression and the association between antidepressant response with endogenous cannabinoids and cytokine levels

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
34

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • United States
    • Texas
      • Houston, Texas, United States, 77030
        • The University of Texas Health Science Center at Houston

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • diagnosis of Bipolar Disorder according to the Diagnostic and Statistical Manual of Mental Disorders (Structured Clinical Interview), Fifth Edition, (DSM5), with a score of ≥16 on the 17-item HAM-D
  • currently in use of at least one FDA approved mood stabilizer with or without antidepressant
  • medically and neurologically healthy on the basis of medical history, physical examination

Exclusion Criteria:

  • Cannabis misuse according to clinical judgement
  • unstable medical condition or uncontrolled medical problem with known central nervous system (CNS) effects
  • active DSM-5 substance use disorder in past three months (other than alcohol or nicotine use disorder)
  • acute high suicidal risk
  • in a manic episode
  • current psychotic features or cognitive impairment that would preclude understanding of the consenting process or tests/examination
  • pregnant or nursing women
  • unstable medical conditions
  • clinically significant abnormal laboratory tests based on complete blood count, liver and kidney function when available

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: PEA plus Treatment as Usual (TAU)
Drug: Palmitoylethanolamide (PEA)
Participants will receive PEA at a dose of 600mg twice daily for 6 weeks.
Drug: Treatment as Usual (TAU)
subjects will receive a mood stabilizer per usual care
Placebo Comparator: Placebo plus Treatment as Usual (TAU)
Drug: Treatment as Usual (TAU)
subjects will receive a mood stabilizer per usual care
Drug: Placebo
Participants will receive placebo (a tablet that contains no active ingredient) to be taken twice daily for 6 weeks

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Change in Depression as Assessed by the Hamilton Depression Rating Scale (HAM-D)
Time Frame: Baseline, 6 weeks follow up
The Hamilton Depression Rating Scale measures severity of depression. The total score ranges from 0 to 26, higher score indicating greater depression severity. The change in score will be reported. The change in score will be reported as the [(Score at 6 weeks follow up) - (Score at Baseline)] - A negative value indicates improvement of depression severity.
Baseline, 6 weeks follow up

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Number of Participants That Show a Remission of Depressive Symptoms as Assessed by the HAM-D Scale
Time Frame: from baseline to end of study (6 week follow up)
Remission of depressive symptoms is defined by a HAM-D score of ≤7. The Hamilton Depression Rating Scale (HAM-D) measures severity of depression. The total score ranges from 0 to 26, higher score indicating greater depression severity
from baseline to end of study (6 week follow up)
Number of Participants That Show a Response as Assessed by the HAM-D Scale
Time Frame: from baseline to end of study (6 week follow up)
Response rate is defined by ≥ 50 % reduction in HAM-D Score from baseline. The Hamilton Depression Rating Scale (HAM-D) measures severity of depression. The total score ranges from 0 to 26, higher score indicating greater depression severity
from baseline to end of study (6 week follow up)
Change in Depression as Assessed by the Montgomery Äsberg Depression Rating Scale (MADRS)
Time Frame: Baseline, 6 weeks follow up
The Montgomery Äsberg Depression Rating Scale measures severity in depression. The total score ranges from 0 to 60, a higher score indicating greater depression. The change in score will be reported. The change in score will be reported as the [(Score at 6 weeks follow up) - (Score at Baseline)] - A negative value indicates improvement of depression severity.
Baseline, 6 weeks follow up
Time to Response - HAM-D (≥50% Reduction From Baseline)
Time Frame: Baseline To Week 6
Time to first study visit at which a participant achieved ≥50% reduction from baseline HAM-D total score. The Hamilton Depression Rating Scale (HAM-D) measures severity of depression. The total score ranges from 0 to 26, higher score indicating greater depression severity
Baseline To Week 6

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Rodrigo Machado-Vieira, MD, PhD, MSc

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Milken Institute
Baszucki Brain Research Fund

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Rodrigo Machado-Vieira, M.D, Ph.D., M.Sc, The University of Texas Health Science Center, Houston

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
May 17, 2023

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
July 17, 2025

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
July 17, 2025

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
January 19, 2024

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
January 19, 2024

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
January 29, 2024

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
August 13, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 10, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
July 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • HSC-MS-21-0989

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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