Effects of THC on Emotional Memory Retrieval (TARE)

The Effects of Δ⁹-Tetrahydrocannabinol on the Retrieval of Emotional Memories

The main purpose of this study was to examine the effects of THC on the retrieval of emotional and neutral memories in healthy young adults. Secondary experiments included the effects of THC on the encoding of object and scene stimuli and a novel working memory task.

Study Overview

• Status: Completed
• Conditions: Healthy
• Intervention / Treatment: Drug: Placebo oral capsule; Drug: THC

Detailed Description

Here, the investigators aimed to investigate the effects of THC (15 mg) on the retrieval of negative, neutral, and positive memories. The study used a placebo-controlled, within-subjects, crossover design with 24 participants. In each experimental arm, participants attend a session to encode stimuli, a second session 48 hours later in which their memories are tested for the stimuli from the first session followed by the encoding of object-scene stimuli and a working memory test, and a third session 48 hours later in which memory for the object-scene stimuli is tested. In the second session, two hours prior to memory testing, THC or placebo is administered. On the first and second sessions subjects complete mood questionnaires.

• Study Type: Interventional
• Enrollment (Actual): 24
• Phase: Early Phase 1

Contacts and Locations

Study Locations

• United States
  • Illinois
    • Chicago, Illinois, United States, 60637
      • University of Chicago

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 35 years (Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• 4-100 lifetime cannabis occasions

Exclusion Criteria:

• Current Axis I DSM-IV disorder, including substance dependence, current use of >5 cigarettes per day, history of psychosis or mania, less than a high school education, lack of English fluency, a body mass index outside 19-33 kg/m2, high blood pressure (>140/90), abnormal electrocardiogram, daily use of any medication other than birth control, pregnancy, or lactating.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Placebo oral capsule; Participants came in for the first session that involved encoding emotional pictures and lists of semantically related words (Deese-Roediger-McDermott or DRM task; a false memory task). Forty-eight hours later, participants received a placebo capsule (dextrose) and waited 2 hours Participants were monitored for the next 2 hours including physiological and subjective measures every 30 minutes. After 2 hours, participants' memory for the emotional stimuli and DRM stimuli was tested. Participants then encoded object stimuli overlaid onto scenes followed by a working memory test with simple color squares. After the memory tests and 3.5 hours post-capsule, if participants' physiological and subjective measures had returned to baseline, they were allowed to leave. Forty-eight hours later, memory for the object-scene stimuli was tested. Other than the capsule, this arm was identical to the THC arm.	Drug: Placebo oral capsule; A capsule that contains only dextrose filler administered 2 hours prior to memory testing.; Other Names: Dextrose
Experimental: THC; Participants came in for the first session that involved encoding emotional pictures and lists of semantically related words (Deese-Roediger-McDermott or DRM task; a false memory task). Forty-eight hours later, participants received a placebo capsule (dextrose) and waited 2 hours Participants were monitored for the next 2 hours including physiological and subjective measures every 30 minutes. After 2 hours, participants' memory for the emotional stimuli and DRM stimuli was tested. Participants then encoded object stimuli overlaid onto scenes followed by a working memory test with simple color squares. After the memory tests and 3.5 hours post-capsule, if participants' physiological and subjective measures had returned to baseline, they were allowed to leave. Forty-eight hours later, memory for the object-scene stimuli was tested. Other than the capsule, this arm was identical to the placebo arm.	Drug: THC; A capsule that contains 15 mg of THC as well as dextrose filler administered 2 hours prior to memory testing.; Other Names: Marinol

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Emotional Memory	Hit and false alarm rates for negative, neutral, and positive picture stimuli	Two hours after placebo/THC administration.
DRM Memory	Hit and false alarm rates for the DRM task	Two and a half hours after placebo/THC administration.
Object Memory	Hit and false alarm rates for object stimuli on the same or different encoding scenes	48 hours after placebo/THC administration.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Addiction Research Centre Inventory Marijuana Scale	The Addiction Research Centre Inventory (ARCI; Martin, Sloan, Sapira, & Jasinski, 1971) measures drug-specific effects on a 56-item true-false questionnaire. For this study, the investigators report the composite score of 12 questions that make up the marijuana scale (Chait, Fischman, & Schuster, 1985).	Assessed just prior to placebo/THC administration and then 30 minutes, 60 minutes, 90 minutes, and 115 minutes after placebo/THC administration.
Visual Analog Scales	The Visual Analog Scales (VAS; Folstein & Luria, 1973) is composed of thirteen adjectives used to assess individual dimensions of subjective mood - anxious, stimulated, sedated, elated, insightful, sociable, confident, lonely, playful, dizzy, loving, friendly, and restless, rated on a sliding scale from 'not at all' to 'extremely.'	Assessed just prior to placebo/THC administration and then 30 minutes, 60 minutes, 90 minutes, and 115 minutes after placebo/THC administration.
Drug Effects Questionnaire	The Drug Effects Questionnaire (DEQ; Morean et al., 2013) is composed of five questions concerning current drug effects - how much participants feel a drug effect, like the effect, dislike the effect, feel high, and want more of the drug, rated on a sliding scale from 'not at all/neutral' to 'very much.'	Assessed just prior to placebo/THC administration and then 30 minutes, 60 minutes, 90 minutes, and 115 minutes after placebo/THC administration.
Physiological Measure 1	Heart rate	Assessed just prior to placebo/THC administration and then 30 minutes, 60 minutes, 90 minutes, and 115 minutes after placebo/THC administration.
Physiological Measure 2	Blood pressure	Assessed just prior to placebo/THC administration and then 30 minutes, 60 minutes, 90 minutes, and 115 minutes after placebo/THC administration.

Collaborators and Investigators

• Sponsor: University of Chicago
• Investigators: Principal Investigator: David A Gallo, PhD, University of Chicago

Publications and helpful links

General Publications

• Doss MK, Weafer J, Gallo DA, de Wit H. Delta9-Tetrahydrocannabinol During Encoding Impairs Perceptual Details yet Spares Context Effects on Episodic Memory. Biol Psychiatry Cogn Neurosci Neuroimaging. 2020 Jan;5(1):110-118. doi: 10.1016/j.bpsc.2019.08.007. Epub 2019 Aug 30.
• Doss MK, Weafer J, Gallo DA, de Wit H. Delta9-Tetrahydrocannabinol at Retrieval Drives False Recollection of Neutral and Emotional Memories. Biol Psychiatry. 2018 Nov 15;84(10):743-750. doi: 10.1016/j.biopsych.2018.04.020. Epub 2018 May 9.

Study record dates

Study Major Dates

• Study Start (Actual): February 15, 2017
• Primary Completion (Actual): October 4, 2017
• Study Completion (Actual): October 4, 2017

Study Registration Dates

• First Submitted: March 7, 2018
• First Submitted That Met QC Criteria: March 13, 2018
• First Posted (Actual): March 20, 2018

Study Record Updates

• Last Update Posted (Actual): May 30, 2019
• Last Update Submitted That Met QC Criteria: May 28, 2019
• Last Verified: March 1, 2018

More Information

Terms related to this study

• Keywords: adult; THC
• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Neurotransmitter Agents; Molecular Mechanisms of Pharmacological Action; Peripheral Nervous System Agents; Analgesics; Sensory System Agents; Analgesics, Non-Narcotic; Hormones; Hormones, Hormone Substitutes, and Hormone Antagonists; Psychotropic Drugs; Hallucinogens; Cannabinoid Receptor Agonists; Cannabinoid Receptor Modulators; Dronabinol
• Other Study ID Numbers: IRB16-1132

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: The investigators have shared all of the data to https://osf.io/e6b5k/
• IPD Sharing Time Frame: The data is already available.
• IPD Sharing Access Criteria: Open to anyone.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No