This study will examine how a moderate dose of THC affects mood, stress responses, and cognitive functioning in regular cannabis users. The study uses a double-blind, placebo-controlled, crossover design, meaning each participant will complete two sessions. Specifically, each participant will be given active cannabis (20 mg THC) in one session, and placebo in the other session. The order will be randomized across participants, so half will receive cannabis first, and the other half will receive placebo first. Ninety adults who use cannabis at least weekly will be recruited from the local community. After an online screening survey, eligible participants will attend a laboratory visit where the participants will provide informed consent and complete saliva and urine drug tests to confirm recent abstinence from cannabis and absence of other drugs. Participants who pass screening will complete baseline questionnaires of cannabis use patterns, depression, anxiety, ADHD symptoms, emotion regulation, affect, and demographic information. Cannabis and placebo materials (obtained from NIDA) will be vaporized using a Volcano vaporizer device. Participants will inhale the vapor under supervision, and neither the participant nor the researcher assessing outcomes will know which product is administered. After vaping, participants will complete repeated mood ratings, saliva samples, and a battery of cognitive tests assessing executive functions like planning, inhibition, working memory, and cognitive flexibility. Participants will also complete a standardized stress challenge (the Maastricht Acute Stress Test), which involves repeated trials of placing their hand in cold water and doing challenging mental math, followed by additional mood ratings and saliva samples. The participants will then watch a nature video and report their feelings of awe and affect. At the end of each session, participants will remain in a supervised room with entertainment and snacks until at least four hours have passed since vaping and the participants report feeling sober. The participants will then return for a second session with the opposite study condition (THC or placebo) one week later. Both sessions follow the same procedures. Participants are fully debriefed after completing the study.
Age range
21 Years
Sex
ALL
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The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
Event-Based Prospective Memory - Number of Difficulty Ratings Provided
Timeframe: This outcome will be assessed during both sessions, within 90 minutes post-treatment.
Time-Based Prospective Memory - Token Task
Timeframe: This outcome will be assessed during both sessions, within 90 minutes post-treatment.
Cognitive Flexibility - N-back Test Accuracy
Timeframe: This outcome will be assessed during both sessions, within 90 minutes post-treatment.
Cognitive Flexibility - N-back Reaction Time
Timeframe: This outcome will be assessed during both sessions, within 90 minutes post-treatment.
Cognitive Flexibility - N-back ERP
Timeframe: This outcome will be assessed during both sessions, within 90 minutes post-treatment.
Verbal Working Memory - Digit Span Backwards
Timeframe: This outcome will be assessed during both sessions, within 90 minutes post-treatment.
Planning - Tower Test Total Achievement Score
Timeframe: This outcome will be assessed during both sessions, within 90 minutes post-treatment.
Planning - Tower Test Rule Violations
Timeframe: This outcome will be assessed during both sessions, within 90 minutes post-treatment.
Planning - Zoo Maps Test Total Achieved Score
Timeframe: This outcome will be assessed during both sessions, within 90 minutes post-treatment.
Planning - Zoo Maps Test Rule Violations
Timeframe: This outcome will be assessed during both sessions, within 90 minutes post-treatment.
Inhibitory Control - Stroop Test Interference Score
Timeframe: This outcome will be assessed during both sessions, within 90 minutes post-treatment.
Inhibitory Control - Stroop Test Accuracy
Timeframe: This outcome will be assessed during both sessions, within 90 minutes post-treatment.
Inhibitory Control - Stroop Test ERP
Timeframe: This outcome will be assessed during both sessions, within 90 minutes post-treatment.
Inhibitory Control - Flanker Test Interference Score
Timeframe: This outcome will be assessed during both sessions, within 90 minutes post-treatment.
Inhibitory Control - Flanker Test Accuracy
Timeframe: This outcome will be assessed during both sessions, within 90 minutes post-treatment.
Inhibitory Control - Flanker Test ERP
Timeframe: This outcome will be assessed during both sessions, within 90 minutes post-treatment.
Cognitive Control - Oddball Task Target Detection Accuracy
Timeframe: This outcome will be assessed during both sessions, within 90 minutes post-treatment.
Cognitive Control - Oddball Task Target Reaction Time
Timeframe: This outcome will be assessed during both sessions, within 90 minutes post-treatment.
Cognitive Control - Oddball Task ERP
Timeframe: This outcome will be assessed during both sessions, within 90 minutes post-treatment.
Cognitive Flexibility - Wisconsin Card Sorting Test Perseverative Errors
Timeframe: This outcome will be assessed during both sessions, within 90 minutes post-treatment.
Cognitive Flexibility - Wisconsin Card Sorting Test Categories Completed
Timeframe: This outcome will be assessed during both sessions, within 90 minutes post-treatment.
Cognitive Flexibility - Wisconsin Card Sorting Test Failure-to-Maintain-Set Errors
Timeframe: This outcome will be assessed during both sessions, within 90 minutes post-treatment.
Cognitive Flexibility - Verbal Fluency, Category Switching Fluency
Timeframe: This outcome will be assessed during both sessions, within 90 minutes post-treatment.
Cognitive Flexibility - Verbal Fluency, Category Switching Accuracy
Timeframe: This outcome will be assessed during both sessions, within 90 minutes post-treatment.
Stressor Challenge - Maastricht Acute Stress Test Subjective Pain Ratings
Timeframe: This outcome will be assessed during both sessions, within 90 minutes post-treatment.
Stressor Challenge - Maastricht Acute Stress Test Subjective Stress Ratings
Timeframe: This outcome will be assessed during both sessions, within 90 minutes post-treatment.
EEG Power
Timeframe: This outcome will be continuously assessed during both sessions, from baseline (i.e., during the testing session but before treatment) through two hours post-treatment.
Awe Ratings
Timeframe: This outcome will be assessed during both sessions, within two hours post-treatment.
Connectedness to Nature Ratings
Timeframe: This outcome will be assessed during both sessions, within two hours post-treatment.