Acute Effects of Cannabis on Cognition and Affect

Starting soon · Phase 2 · Has a placebo group

Conditions studied: Cannabis Use

In brief

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.

Key facts

Study ID: NCT07296874
Run by: Washington State University
People needed: 90
Starts: 2026-07-01
Expected to finish: 2028-05-01
Last updated by the study team: 2026-06-01

Who can join

Age: 21 and older. Sex: any. Healthy volunteers: accepted.

You may qualify if…

be 21 years of age or older
be fluent in English
use of cannabis at least once a week for at least one year
inhalation as their typical method of administration
be willing to abstain from cannabis on the day of their scheduled testing session

You may not qualify if…

neurological conditions (e.g., neurodegenerative disorders, severe head injury, multiple concussions)
serious psychiatric conditions (e.g., psychosis, bipolar disorder)
family history of psychosis
intellectual disabilities or learning disorders (e.g., dyslexia)
chronic medical conditions that affect cognition or increase risk of cannabis use or exposure to cold water (e.g., heart disease, diabetes, Reynaud's disease, history of frostbite, peripheral neuropathy, history of fainting or seizures, fractures or wounds on both hands or wrists),
heart disease
BMI > 34
pregnant or lactating
use of illicit drugs in past 6 months
heavy use of alcohol (drinking >4 drinks >4 times per week)
nicotine/tobacco use
have experienced a severe adverse reaction to cannabis (e.g., panic attack, psychosis)

Where it is running

Washington State University — Pullman, Washington, United States

Full record on ClinicalTrials.gov

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