Cannabis (smoked flower)
Self-Directed Use (ad-libitum)
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This study investigates the impact of ∆9-tetrahydrocannabinol (THC) and cannabidiol (CBD) on recognition memory in healthy, regular cannabis users. Participants complete the same recognition memory task after self-administering one of two different strains of cannabis flower one day and while not intoxicated another day. Event-related potentials (ERPs) are measured via electroencephalogram (EEG) during the recognition memory task. Blood is collected to quantify THC and CBD exposure. Participants also complete self-report measures of medical history, sleep quality, subjective cognitive function, physical activity, psychological functioning, substance use, and acute drug effects.
Locally preserved from ClinicalTrials.govOpen ClinicalTrials.govlast source update 2026-05-12
What this record can show
This locally preserved record separates the registered protocol from source-reported registry results. Neither is a treatment recommendation.
Registry facts
Previous research has established cannabis's harmful cognitive impact, with particularly robust and consistent effects in the domain of episodic memory. However, prior work has not sufficiently considered that the memory effects of cannabis are the compound action of different cannabinoids, which vary in their pharmacology and effects. Specifically, CBD, a non-psychotomimetic component of cannabis (doesn't produce a "high"), is thought to have cognitively protective properties and may mitigate some of the harmful effects of THC. Further, few prior studies have tested the effects of high potency strains that are commonly available. This study tests the effects of commercially available cannabis flower strains on recognition memory performance and ERPs that are related to different underlying memory processes in healthy, regular cannabis users. An episodic memory task is used to assess recognition memory, which asks participants to discriminate between previously studied and non-studied items using pictures as stimuli. Participants complete the same memory task while intoxicated one day and not intoxicated another day. A THC-dominant strain and a strain containing both THC and CBD are included in the study. Participants self-administer one of the two cannabis strains prior to memory encoding and retrieval. Blood is collected to determine THC and CBD exposure, as well as to explore how genetic variation in genes related to cannabinoid metabolism, cannabis-related behavior, and neurocognitive function associate with memory function before and after cannabis use. Participants also complete self-report measures of medical history, sleep quality, subjective cognitive function, physical activity, psychological functioning, substance use, and acute drug effects.
Linked local records
Local links use governed condition terms or exact source-reported intervention names. They are navigation candidates, not efficacy claims.
Interventions
Self-Directed Use (ad-libitum)
Eligibility
Community sample of healthy, regular cannabis users in the Boulder and Denver areas
primary outcomes
Time frame: Intoxicated session and not-intoxicated session (about 1 week)
Electroencephalography is used to quantify FN400.
Time frame: Intoxicated session and not-intoxicated session (about 1 week).
Electroencephalography is used to quantify parietal ERP effects.
Time frame: Intoxicated session and not-intoxicated session (about 1 week)
Accuracy will be used to assess task performance.
Time frame: Intoxicated session and not-intoxicated session (about 1 week)
Reaction time will be used to assess task performance.
secondary outcomes
Time frame: Before and after acute cannabis use during intoxicated session
The PANAS is Self-report measurement of positive and negative affect. Both subscales range from 1 - 50, with a higher score on the positive affect scale indicating higher positive affect and a higher score on the negative affect scale indicating higher negative affect.
Time frame: Before and after acute cannabis use during intoxicated session
The DEQ is a visual analogue scale of measure of acute drug effects. Participants are asked 5 questions on the DEQ, each of which range from 0 - 100, with higher values for each item indicating greater drug effect.
Time frame: Before and after acute cannabis use during intoxicated session
The ARCI-M is a self-report measure of subjective effects of marijuana. This is a 12-item true-false task, in which higher (true) scores indicate greater intoxication.
Time frame: Before and after acute cannabis use during intoxicated session
The Marijuana Craving Questionnaire is a self-report measure of marijuana craving. Participants complete 8 questions ranging from 0 - 10, with a higher score indicating greater cannabis craving and somatic symptoms.
Time frame: Before and after acute cannabis use during intoxicated session
The POMS is a self-report measure of mood. Participants complete 27 mood-related items ranging from 0 - 4, with higher scores indicating greater levels of specific mood states.
Time frame: Before and after acute cannabis use during intoxicated session
The Alcohol Craving Questionnaire is a self-report measure of alcohol craving. This is a 2-item scale with each item ranging 0 - 10, with higher scores indicating greater alcohol craving.
Time frame: Before and after acute cannabis use during intoxicated session
The SAPC-B is a self-report measure of paranoia. Participants complete 5 items each ranging from 0 - 10, with higher scores indicating greater feelings of paranoia.
Time frame: Baseline, intoxicated session, and not-intoxicated session (about 3 weeks total over all three sessions)
Blood levels of THC and CBD will be quantified.
other outcomes
Time frame: Baseline, intoxicated session, and not-intoxicated session (about 3 weeks total over all three sessions)
DNA samples are collected from a baseline blood sample.
Time frame: Baseline, intoxicated session, and not-intoxicated session (about 3 weeks total over all three sessions)
This is a baseline measure of participant sleep disturbance. Participants complete 4 items, for a total scale score from 4 - 20, with higher scores indicating more sleep disturbance.
Time frame: Baseline, intoxicated session, and not-intoxicated session (about 3 weeks total over all three sessions)
This is a baseline measure of affective symptoms. Participants complete three separate subscales assessing depression, anxiety, and stress, each with 7 items and with higher scores indicating greater levels of depression, anxiety, and stress.
Time frame: Baseline, intoxicated session, and not-intoxicated session (about 3 weeks total over all three sessions)
This is a baseline measure of substance use history. Participants report their substance use over the last 30 days prior to the baseline appointment.
Publications
No exact PMID-linked public article is currently readable locally.