Effects of THC on Emotional Memory Retrieval
- Registration Number
- NCT03471585
- Lead Sponsor
- University of Chicago
- Brief Summary
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.
- 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.
Recruitment & Eligibility
- Status
- COMPLETED
- Sex
- All
- Target Recruitment
- 24
- 4-100 lifetime cannabis occasions
- 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 & Design
- Study Type
- INTERVENTIONAL
- Study Design
- CROSSOVER
- Arm && Interventions
Group Intervention Description Placebo oral capsule 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. THC 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.
- Primary Outcome Measures
Name Time Method Object Memory 48 hours after placebo/THC administration. Hit and false alarm rates for object stimuli on the same or different encoding scenes
DRM Memory Two and a half hours after placebo/THC administration. Hit and false alarm rates for the DRM task
Emotional Memory Two hours after placebo/THC administration. Hit and false alarm rates for negative, neutral, and positive picture stimuli
- Secondary Outcome Measures
Name Time Method Addiction Research Centre Inventory Marijuana Scale Assessed just prior to placebo/THC administration and then 30 minutes, 60 minutes, 90 minutes, and 115 minutes after placebo/THC administration. 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).
Physiological Measure 1 Assessed just prior to placebo/THC administration and then 30 minutes, 60 minutes, 90 minutes, and 115 minutes after placebo/THC administration. Heart rate
Physiological Measure 2 Assessed just prior to placebo/THC administration and then 30 minutes, 60 minutes, 90 minutes, and 115 minutes after placebo/THC administration. Blood pressure
Visual Analog Scales Assessed just prior to placebo/THC administration and then 30 minutes, 60 minutes, 90 minutes, and 115 minutes after placebo/THC administration. 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.'
Drug Effects Questionnaire Assessed just prior to placebo/THC administration and then 30 minutes, 60 minutes, 90 minutes, and 115 minutes after placebo/THC administration. 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.'
Trial Locations
- Locations (1)
University of Chicago
🇺🇸Chicago, Illinois, United States