Examining the Role of Tolerance on Dose-dependent Effects of Acute THC on Oculomotor and Cognitive Performance

May 26, 2026 updated by: Johns Hopkins University
The purpose of this research is to determine the extent to which oculomotor function accurately detects THC-impairment, if cannabis use experience impacts this detection threshold, and to examine how the oculomotor index corresponds to a measure of sustained attention. A double-blind, placebo-controlled, within-subjects crossover design will be used to examine the dose-effects of THC (0, 5mg, 30mg) on oculomotor performance tasks and a sustained attention task in frequent and infrequent cannabis users. Results from the study will advance the investigators' understanding of the effect of THC and cannabis use frequency on oculomotor function and sustained attention, and will directly inform the validity of the investigators' oculomotor platform for identifying acute THC- induced impairment in frequent and infrequent users.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

40

Phase

  • 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 Locations

  • United States
    • Maryland
      • Baltimore, Maryland, United States, 21224
        • Johns Hopkins Behavioral Pharmacology Research Unit

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

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Inclusion criteria: Healthy non-treatment seeking adults (age 18 to 60, N = 40) who report
  • (a) infrequent cannabis use defined as at least one reported use in the past year with a negative THC urine toxicology at baseline, or
  • (b) report frequent cannabis use defined as > 5 days per week for > 1 year with a positive THC urine toxicology at baseline.

These criteria were selected to target individuals with low and high-frequency cannabis use in order to examine the direct effect of tolerance on study outcome measures.

Exclusion Criteria:

  • (1) meet DSM-V criteria for substance use disorders other than tobacco, cannabis, or caffeine,
  • (2) are currently receiving or interested in immediately receiving behavioral treatment or medication for cannabis cessation,
  • (3) current use of any medications that could affect study outcomes,
  • (4) test positive for drugs of abuse (other than cannabis) and/or breath alcohol test at study admission,
  • (5) have a current physical or mental illness judged by the study team to negatively impact participant safety or scientific integrity,
  • (6) are currently pregnant, planning to become pregnant in the next three months or are currently breastfeeding,
  • (7) have a history of clinically significant cardiac arrhythmias or vasospastic disease (e.g. Prinzmetal's angina), or (8) are currently enrolled in another clinical trial or have received any drug as part of a research study within 30 days of study participation.

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: Basic Science
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Placebo Comparator: 0 mg THC
Inhaled Cannabis - 0 mg THC
Drug: Cannabis
cannabis with 0, 5, or 30 mg THC will be inhaled via vaporization
Experimental: 5 mg THC
Inhaled cannabis - 5 mg THC
Drug: Cannabis
cannabis with 0, 5, or 30 mg THC will be inhaled via vaporization
Experimental: 30 mg THC
Inhaled cannabis - 30 mg THC
Drug: Cannabis
cannabis with 0, 5, or 30 mg THC will be inhaled via vaporization

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Commission Errors
Time Frame: pre-administration, post-administration, 2, 4 hours
The Conners Continuous Performance Test (CPT) will be used to assess sustained attention. Commission errors is measured by calculating the number of trials participants incorrectly push the spacebar in the presence of "X" stimulus.
pre-administration, post-administration, 2, 4 hours
Omission Errors
Time Frame: pre-administration, post-administration, 2, 4 hours
The Conners Continuous Performance Test (CPT) will be used to assess sustained attention. Omission errors is measured by calculating the number of trials participants fail to push the spacebar in the presence of a letter that is not an "X" stimulus.
pre-administration, post-administration, 2, 4 hours
Reaction Time
Time Frame: pre-administration, post-administration, 2, 4 hours
The Conners Continuous Performance Test (CPT) will be used to assess sustained attention. Reaction time is measured by calculating the duration between the presentation of a letter other than "X", and the correct response of a spacebar push.
pre-administration, post-administration, 2, 4 hours
Reaction Time Standard Error
Time Frame: pre-administration, post-administration, 2, 4 hours
The Conners Continuous Performance Test (CPT) will be used to assess sustained attention. Reaction time standard error is measured by calculating the standard error of the mean of the reaction time.
pre-administration, post-administration, 2, 4 hours
Visuomotor Index
Time Frame: pre-administration, post-administration, 2, 4 hours
The visuomotor index score is calculated by mathematically integrating five measures of oculomotor fixation performance and two measures of accuracy into a single score during fixation and accuracy tasks, respectively. Test of visual fixation to measure microsaccades, spontaneous nystagmus, and gaze-evoked nystagmus.
pre-administration, post-administration, 2, 4 hours

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Saccade Speed
Time Frame: Pre-administration, post-administration, 2, 4 hours
Measures how quickly participants look back and forth between two spots as possible during the oculomotor task.
Pre-administration, post-administration, 2, 4 hours
Visually Guided Oculomotor Performance
Time Frame: Pre-administration, post-administration, 2, 4 hours
Measures how quickly and accurately participants move their eyes to a cue as soon as it appears on the oculomotor task.
Pre-administration, post-administration, 2, 4 hours
Antisaccade
Time Frame: Pre-administration, post-administration, 2, 4 hours
Measures voluntary eye movement in the direction opposite to the side in which a visual cue is presented.
Pre-administration, post-administration, 2, 4 hours
Memory-Guided
Time Frame: Pre-administration, post-administration, 2, 4 hours
Measures how quickly gaze is shifted directly and accurately to a remembered cue position.
Pre-administration, post-administration, 2, 4 hours

Collaborators and Investigators

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

Sponsor

Johns Hopkins University

Collaborators

National Institute on Drug Abuse (NIDA)

Investigators

  • Principal Investigator: Dustin C Lee, PhD, Johns Hopkins University

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)

August 1, 2026

Primary Completion (Estimated)

July 1, 2027

Study Completion (Estimated)

July 1, 2027

Study Registration Dates

First Submitted

April 2, 2024

First Submitted That Met QC Criteria

April 5, 2024

First Posted (Actual)

April 8, 2024

Study Record Updates

Last Update Posted (Actual)

May 27, 2026

Last Update Submitted That Met QC Criteria

May 26, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • IRB00332797
  • R21DA056687 (U.S. NIH Grant/Contract)

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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