Shortened LSD Intervention for Major Depressive Disorder (SLIM)

July 23, 2026 updated by: Johns Hopkins University
The purpose of this study is to determine the safety and clinical effectiveness of a shortened lysergic acid diethylamide (LSD) experience. This will be achieved by administering the drug risperidone 45-minutes after the administration of LSD.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

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.

Detailed Description

This study will administer open-label oral LSD hemi-L-tartrate 250 µg followed 45 minutes later by oral risperidone 1 mg to 10 participants with Major Depressive Disorder (MDD) for a pilot investigation into the effects of abbreviated LSD on depression. Participants will be monitored for 10.5 hours and assessed for subjective effects and discharge readiness at several time points following the dose. The main aim of this study is to test whether risperidone can be used to abbreviate the subjective effects of LSD, and whether this abbreviated LSD experience will have any potential therapeutic benefit in patients with MDD.

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 (Estimated)

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.
10

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 1

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 Locations

  • United States
    • Maryland
      • Baltimore, Maryland, United States, 21224
        • Johns Hopkins Center for Psychedelic and Consciousness Research
        • Contact:
        • Principal Investigator:
          • Sandeep Nayak, MD

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:

  • Have given written informed consent
  • Meet DSM-5 criteria for MDD
  • MADRS >= 28 at screening Can read, write, and speak English fluently
  • Be judged by study team clinicians to be at low risk for suicidality

Exclusion Criteria:

  • Women who are pregnant, nursing, or not practicing an effective means of birth control
  • Cardiovascular conditions: hypertension with resting blood pressure systolic >139 or diastolic >89, angina, heart rate > 99, a clinically significant ECG abnormality (e.g., atrial fibrillation, QTc > 450), TIA in the last 6 months stroke, peripheral or pulmonary vascular disease, cardiac valvulopathy
  • Epilepsy
  • Insulin-dependent diabetes; if taking oral hypoglycemic agent, then no history of hypoglycemia
  • Currently taking antipsychotics, or MAO inhibitors
  • Patients taking antidepressant medications and unable to taper
  • Moderate or strong CYP2D6 inhibitor antidepressants must undergo a washout period of 4 weeks or five half-lives prior to treatment
  • Currently taking CYP2D6 inhibitor other than an antidepressant that will be tapered
  • Currently taking efavirenz, Acetaldehyde dehydrogenase inhibitors such as disulfiram (Antabuse), Alcohol dehydrogenase inhibitors, or UGT1A9 inhibitors or UGT1A10 inhibitors such as phenytoin, regorafenib, eltrombopag
  • Have a seizure disorder, multiple sclerosis, history of significant head trauma, CNS tumor, movement disorders or any neurodegenerative condition
  • Morbidly obese (>100 lbs. above ideal body weight, or BMI >=40, or BMI >=35 with high blood pressure or diabetes)
  • Be judged by a study team clinician to be at risk for moderate or severe alcohol or benzodiazepine withdrawal
  • Body weight < 45 kg
  • Significant acute adverse reaction (e.g., dystonia) to an antipsychotic
  • Current or past history of meeting DSM-5 criteria for Schizophrenia, Psychotic Disorder (including substance-induced), Bipolar I or II Disorder or Major
  • Depression with psychotic features
  • Have a first degree relative with schizophrenia, psychotic disorder (unless substance induced or due to a medical condition), or Bipolar I Disorder.

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: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

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: LSD + Risperidone
Drug: LSD
Participants will be administered LSD followed 45-minutes later by risperidone.
Drug: Risperidone
Participants will be administered LSD followed 45-minutes later by risperidone.

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 Montgomery Asberg Depression Rating Scale (MADRS)
Time Frame: 1 month
Score range from 0 to 60. Higher scores indicate worse depression symptoms
1 month

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.
Johns Hopkins University

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: Sandeep Nayak, MD, Johns Hopkins University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Helpful Links

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 (Estimated)

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.
August 31, 2026

Primary Completion (Estimated)

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 1, 2027

Study Completion (Estimated)

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.
December 1, 2027

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).
March 25, 2026

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.
March 25, 2026

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.
March 31, 2026

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.
July 24, 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.
July 23, 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.
  • IRB00460674

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

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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