Memory
Conditions
Brief summary
The main objectives of this study were to test if a singular dose of Cannabidiol (1) enhances the learning and memory of healthy human subjects, (2) test if Cannabidiol has negative effects on Retroactive and Proactive Interference during learning, (3) and test if demographic factors will influence CBD's modulation of human learning and memory.
Detailed description
Using a randomized, double-blind, placebo-controlled two-arm case-crossover trial, this study investigates the effect of 246 milligrams (mg) of Cannabidiol (CBD) on the learning and memory scores of human subjects, as well as the effect of Cannabidiol on Proactive and Retroactive Interference. This study also investigated the influence of demographic factors on CBD's modulation of human learning and memory. This study was conducted at Colorado State University-Pueblo (CSU Pueblo) with volunteers recruited from CSU Pueblo and the local Pueblo community. Fifty-seven subjects were randomized in a double-blind manner to receive either CBD or placebo before completing two versions of learning and memory assessments. Each version of the learning and memory assessment included the Montreal Cognitive Assessment (MOCA), the Rey Auditory Verbal Learning Task-Revised (RAVLT-R), and the Logical Memory Subject of the Weschler Memory Scale. Several components of the RAVLT-R were evaluated including the Sum of Trials (Trials I-V) score, Proactive Interference Ratio (PI Ratio), and Retroactive Interference (RI Ratio).
Interventions
DRUGCannabidiol (246mg press pill)
Cannabidiol press pills provided by Steve Goods CBD (Longmont, Colorado). CBD pills were tested by the chemistry lab at CSU Pueblo and by Botanacor in Denver, CO. Both laboratories determined CBD pills to be 99.98% pure with no THC, heavy metals, bacteria, and pesticides detected.
DRUGPlacebo (246mg press pill)
Placebo press pills were provided by Steve Goods CBD (Longmont, Colorado). Placebo pills were tested by the chemistry lab at CSU Pueblo and by Botanacar in Denver, CO. Both laboratories determined placebo pills to be pure with no heavy metals, bacteria, and pesticides detected.
Sponsors
Institute of Cannabis Research
Colorado State University
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
TRIPLE (Subject, Caregiver, Outcomes Assessor)
Masking description
Triple (Participant, Care Provider, Outcomes Assessor)
Intervention model description
Two-arm Case-Crossover
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
* Were 18 years of age or older
Exclusion criteria
* Were pregnant or breast-feeding * Had been diagnosed with mental illness * Didn't speak English fluently * Had severe hearing problems * Had recreational or opioid drug contaminants in their urine * Were involved in criminal activity
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Sum of Trials (I-V) | Each trial is 45 seconds for encoding and recall | Sum of Trials = Trial A1 + Trial A2 + Trial A3 + Trial A4 + Trial A5; Trial A1/A2/A3/A4/A5 are in reference to each trial in which list A is recalled during memory encoding. The score range for Sum of Trials is 0 to 75. A higher score is indicative of greater performance on the memory test and a lower score is indicative of lower performance on the memory test. Participants were instructed to listen to a list of 15 words (List A) read to them. Subjects were asked recall List A during five different trials (A1, A2, A3, A4, A5), with the words repeated to them after each trial. Participants were scored for the number of correctly repeated words for each trial. |
| Proactive Interference Ratio (PI Ratio) | Each trial is 45 seconds for encoding and recall | PI Ratio = Trial B1/A1. Proactive interference is the tendency for previously learned information to affect to hinder learning of new information. A higher proactive interference ratio indicates protective effects on memory i.e. protection from interference during learning. A lower proactive interference is indicative of negative effects on memory caused from interference. Trial A1 is in reference to list A recall during the first trial. Trial B1 is in reference to list B recall. Highest score for each trial is 15 with a point awarded for each correctly recalled word from List A (15 words) and List B (15 words). |
| Retroactive Interference Ratio (RI Ratio) | Each trial is 45 seconds for encoding and recall | RI Ratio = Trial A6/A5. Retroactive interference is the tendency for newly learned information to hinder the memory of previously learned information. A higher retroactive interference ratio indicates protection from interference during learning. A lower retroactive interference ratio is indicative of negative effects on memory caused from interference. Trial A6 is referring to delayed recall of list A; Trial A5 is referring to the fifth trial of list A recall. Highest score for each trial is 15 with a point awarded for each word correctly recalled from List A (15 words). |
| Total Prose Recall | Each recall takes about 5 min for encoding and recall | Total Prose Recall = Immediate Recall + Delayed Recall; Recall of a prose story was done immediately then after a delay; Highest score for prose recall test is 25 with a point awarded for each item correctly recalled in the story (25 total items). A higher recall score is indicative of better memory. |
| Montreal Cognitive Assessment Score | 10 minutes total for encoding and recall | Assessment of basal cognitive function; The range for Montreal Cognitive Assessment (MOCA) scores is 0 to 30. A higher recall score is indicative of better performance on the memory test. A lower recall score is indicative of worse performance on the memory test. |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Placebo First, Then Cannabidiol 246mg Placebo, oral, single-dose (visit 1 or visit 2 drug administration)
Placebo in Oral Dose Form: Placebo press pills provided by Steve Goods CBD (Longmont, Colorado). Placebo pills were tested by the chemistry lab at CSU Pueblo and by Botanacar in Denver, CO. Both laboratories determined placebo pills to be pure with no heavy metals, bacteria, and pesticides detected. | 16 |
| Cannabidiol First, Then Placebo 246mg Cannabidiol, oral single-dose (visit 1 or visit 2 drug administration)
Cannabidiol in Oral Dose Form: Cannabidiol press pills provided by Steve Goods CBD (Longmont, Colorado). CBD pills were tested by the chemistry lab at CSU Pueblo and by Botanacor in Denver, CO. Both laboratories determined CBD pills to be 99.98% pure with no THC, heavy metals, bacteria, and pesticides detected. | 19 |
| Total | 35 |
Baseline characteristics
| Characteristic | Placebo First, Then Cannabidiol | Cannabidiol First, Then Placebo | Total |
|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical Between 18 and 65 years | 16 Participants | 19 Participants | 35 Participants |
| Age, Continuous | 27 years | 33 years | 30 years |
| Ethnicity (NIH/OMB) Hispanic or Latino | 5 Participants | 9 Participants | 14 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 11 Participants | 10 Participants | 21 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants |
| History of CBD Use, categorical Non-user | 12 Participants | 16 Participants | 28 Participants |
| History of CBD Use, categorical User | 4 Participants | 3 Participants | 7 Participants |
| History of Nicotine Use, categorical Non-user | 14 Participants | 15 Participants | 29 Participants |
| History of Nicotine Use, categorical User | 2 Participants | 4 Participants | 6 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants | 1 Participants | 1 Participants |
| Race (NIH/OMB) Black or African American | 2 Participants | 4 Participants | 6 Participants |
| Race (NIH/OMB) More than one race | 2 Participants | 4 Participants | 6 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) White | 12 Participants | 10 Participants | 22 Participants |
| Region of Enrollment United States | 16 participants | 19 participants | 35 participants |
| Sex: Female, Male Female | 8 Participants | 11 Participants | 19 Participants |
| Sex: Female, Male Male | 8 Participants | 8 Participants | 16 Participants |
| Urine THC Result, categorical THC - | 7 Participants | 12 Participants | 19 Participants |
| Urine THC Result, categorical THC + | 9 Participants | 7 Participants | 16 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 35 | 0 / 35 |
| other Total, other adverse events | 1 / 35 | 4 / 35 |
| serious Total, serious adverse events | 0 / 35 | 0 / 35 |
Outcome results
Primary
Montreal Cognitive Assessment Score
Assessment of basal cognitive function; The range for Montreal Cognitive Assessment (MOCA) scores is 0 to 30. A higher recall score is indicative of better performance on the memory test. A lower recall score is indicative of worse performance on the memory test.
Time frame: 10 minutes total for encoding and recall
Population: Adult healthy human population
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Placebo (Administered During Visits 1 or 2) | Montreal Cognitive Assessment Score | 26.31 Score on a scale | Standard Error 0.46 |
| Cannabidiol (Administered During Visits 1 or 2) | Montreal Cognitive Assessment Score | 26.63 Score on a scale | Standard Error 0.46 |
Primary
Proactive Interference Ratio (PI Ratio)
PI Ratio = Trial B1/A1. Proactive interference is the tendency for previously learned information to affect to hinder learning of new information. A higher proactive interference ratio indicates protective effects on memory i.e. protection from interference during learning. A lower proactive interference is indicative of negative effects on memory caused from interference. Trial A1 is in reference to list A recall during the first trial. Trial B1 is in reference to list B recall. Highest score for each trial is 15 with a point awarded for each correctly recalled word from List A (15 words) and List B (15 words).
Time frame: Each trial is 45 seconds for encoding and recall
Population: Adult healthy human subjects
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Placebo (Administered During Visits 1 or 2) | Proactive Interference Ratio (PI Ratio) | 1.04 ratio | Standard Error 0.08 |
| Cannabidiol (Administered During Visits 1 or 2) | Proactive Interference Ratio (PI Ratio) | 1.21 ratio | Standard Error 0.08 |
p-value: 0.008Linear Mixed Model
Primary
Retroactive Interference Ratio (RI Ratio)
RI Ratio = Trial A6/A5. Retroactive interference is the tendency for newly learned information to hinder the memory of previously learned information. A higher retroactive interference ratio indicates protection from interference during learning. A lower retroactive interference ratio is indicative of negative effects on memory caused from interference. Trial A6 is referring to delayed recall of list A; Trial A5 is referring to the fifth trial of list A recall. Highest score for each trial is 15 with a point awarded for each word correctly recalled from List A (15 words).
Time frame: Each trial is 45 seconds for encoding and recall
Population: Adult healthy human subjects
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Placebo (Administered During Visits 1 or 2) | Retroactive Interference Ratio (RI Ratio) | 0.87 ratio | Standard Error 0.03 |
| Cannabidiol (Administered During Visits 1 or 2) | Retroactive Interference Ratio (RI Ratio) | 0.83 ratio | Standard Error 0.03 |
Primary
Sum of Trials (I-V)
Sum of Trials = Trial A1 + Trial A2 + Trial A3 + Trial A4 + Trial A5; Trial A1/A2/A3/A4/A5 are in reference to each trial in which list A is recalled during memory encoding. The score range for Sum of Trials is 0 to 75. A higher score is indicative of greater performance on the memory test and a lower score is indicative of lower performance on the memory test. Participants were instructed to listen to a list of 15 words (List A) read to them. Subjects were asked recall List A during five different trials (A1, A2, A3, A4, A5), with the words repeated to them after each trial. Participants were scored for the number of correctly repeated words for each trial.
Time frame: Each trial is 45 seconds for encoding and recall
Population: The data reported is for 35 adult healthy human subjects who came in for visits 1 and 2 and were randomized to a treatment group (CBD or placebo). Since the 35 subjects came in twice, each of them received both interventions (CBD and placebo).
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Placebo (Administered During Visits 1 or 2) | Sum of Trials (I-V) | 49.09 score on a scale | Standard Error 1.85 |
| Cannabidiol (Administered During Visits 1 or 2) | Sum of Trials (I-V) | 47.17 score on a scale | Standard Error 1.85 |
Primary
Total Prose Recall
Total Prose Recall = Immediate Recall + Delayed Recall; Recall of a prose story was done immediately then after a delay; Highest score for prose recall test is 25 with a point awarded for each item correctly recalled in the story (25 total items). A higher recall score is indicative of better memory.
Time frame: Each recall takes about 5 min for encoding and recall
Population: Adult healthy human subjects
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Placebo (Administered During Visits 1 or 2) | Total Prose Recall | 27.49 Score on a scale | Standard Error 1.46 |
| Cannabidiol (Administered During Visits 1 or 2) | Total Prose Recall | 25.49 Score on a scale | Standard Error 1.46 |