Examining the Role of Tolerance on Dose-dependent Effects of Acute THC on Oculomotor and Cognitive Performance
- Conditions
- Cannabis UseCognitive ImpairmentImpaired Driving
- Interventions
- Registration Number
- NCT06351540
- Lead Sponsor
- Johns Hopkins University
- Brief Summary
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.
- Detailed Description
Not available
Recruitment & Eligibility
- Status
- NOT_YET_RECRUITING
- Sex
- All
- Target Recruitment
- 40
- 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.
- (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 & Design
- Study Type
- INTERVENTIONAL
- Study Design
- CROSSOVER
- Arm && Interventions
Group Intervention Description 5 mg THC Cannabis Inhaled cannabis - 5 mg THC 30 mg THC Cannabis Inhaled cannabis - 30 mg THC 0 mg THC Cannabis Inhaled Cannabis - 0 mg THC
- Primary Outcome Measures
Name Time Method Reaction Time 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.
Commission Errors 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.
Omission Errors 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.
Visuomotor Index 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.
Reaction Time Standard Error 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.
- Secondary Outcome Measures
Name Time Method Saccade Speed Pre-administration, post-administration, 2, 4 hours Measures how quickly participants look back and forth between two spots as possible during the oculomotor task.
Visually Guided Oculomotor Performance 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.
Antisaccade 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.
Memory-Guided Pre-administration, post-administration, 2, 4 hours Measures how quickly gaze is shifted directly and accurately to a remembered cue position.
Trial Locations
- Locations (1)
Johns Hopkins Behavioral Pharmacology Research Unit
🇺🇸Baltimore, Maryland, United States