Marijuana's Impact on Alcohol Motivation and Consumption

This laboratory study will employ a repeated measures experimental design to examine the effect of high (7.2% THC) and moderate (3.1% THC) dose of marijuana, relative to placebo, on alcohol craving and on behavioral economic measure of alcohol demand after exposure to alcohol cues, and on subsequent drinking in an alcohol choice task in which participants choose either to drink or receive monetary reinforcement for drinks not consume. The study will recruit 173 non-treatment seeking heavy episodic alcohol drinkers who smoke marijuana at least twice weekly.

Study Overview

• Status: Completed
• Conditions: Alcohol Drinking; Marijuana
• Intervention / Treatment: Drug: THC 7.2%; Drug: Placebo; Drug: THC 3.1%

Detailed Description

This laboratory study will employ a repeated measures experimental design to examine the effect of high (7.2% THC) and moderate (3.1% THC) dose of marijuana, relative to placebo, on alcohol craving and on behavioral economic measure of alcohol demand after exposure to alcohol cues, and on subsequent drinking in an alcohol choice task in which participants choose either to drink or receive monetary reinforcement for drinks not consumed. Moderators of the marijuana's effects on alcohol-related dependent variables will be tested: DSM5 alcohol use disorder severity, affective vulnerability, trait impulsivity, and working memory functioning. Several empirically-determined mechanisms that may explain why marijuana may increase risk of alcohol relapse and help maintain heavy drinking will be tested as mediators of marijuana's effects on alcohol. The study will recruit 173 non-treatment seeking heavy episodic alcohol drinkers who smoke marijuana at least twice weekly to obtain the final sample of 150 with complete data (15% of attrition). Participants will be tested at a baseline session and during three experimental sessions. Investigators will collect blood samples for analysis of cannabinoid plasma levels and to examine marijuana-induced changes in hormones and other biomarkers potentially related to appetite, inflammation and stress. Collection of these biomarkers would allow for a greater understanding about the mechanisms whereby marijuana may acutely increase alcohol motivation and use. The findings will inform researchers and clinicians about how marijuana acutely increases alcohol craving and consumption. The strategy of this proposal is to use the most comprehensive controlled test characterizing marijuana's putative effects on alcohol.

• Study Type: Interventional
• Enrollment (Actual): 157
• Phase: Phase 2

Contacts and Locations

Study Locations

• United States
  • Rhode Island
    • Providence, Rhode Island, United States, 02912
      • Brown University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 21 years to 44 years (Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Age 21 to 44
• English-speaking
• marijuana smoking in past month
• report of current heavy episodic (binge) drinking
• in good physical health and weighing < 250 lbs
• zero breath alcohol at each visit

Exclusion Criteria:

• history of seizures
• smoking >20 tobacco cigarettes per day
• positive pregnancy test
• nursing
• positive urine toxicology screen for drugs other than cannabis
• interest to quit or receive treatment for marijuana or alcohol use
• meeting criteria for a current affective disorder (depression, or mania, panic disorder, and having psychotic symptoms as assessed by the SCID)

Study Plan

How is the study designed?

Design Details

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

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Placebo; Placebo marijuana cigarette	Drug: Placebo; 1 smoked placebo marijuana cigarette
Experimental: 7.2% THC; 1 marijuana cigarette (7.2% THC)	Drug: THC 7.2%; 1 smoked marijuana cigarette with 7.2% THC
Experimental: 3.1% THC; 1 marijuana cigarette (3.1% THC)	Drug: THC 3.1%; 1 smoked marijuana cigarette with 3.0% THC

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Alcohol Craving	Alcohol Craving Questionnaire-Short Form-Revised (ACQ-SF-R) is a 12-item state measure of alcohol craving in the current moment (i.e., right now), scored on a 7-point Likert scale, from (1) strongly disagree to (7) strongly agree, with higher scores indicating greater craving. Scores on this measure are averaged to yield a total craving score.	T0: pre-smoking (-45 minutes) and post smoking at 12 mins (T1), 47 mins (T2), and 58 mins (T3), 116 mins (T4), 178 mins (T5) during the experimental session

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Percent of Total Available Alcohol Consumed	Participants completed two 60-minute blocks in the bar lab, during which they could drink up to eight mini-drinks of their personal choice with total amount of alcohol available designed to raise blood levels up to 0.10 g/dl or receive monetary reinforcement (in each block $12 tab in which each drink is worth $3) for drinks not consumed. The primary dependent variable for this task is percent of total available alcohol consumed.	post-smoking during two-hour alcohol choice task during the experimental session

Collaborators and Investigators

• Sponsor: Brown University
• Collaborators: National Institute on Alcohol Abuse and Alcoholism (NIAAA)
• Investigators: Principal Investigator: Jane Metrik, PhD, Brown University

Study record dates

Study Major Dates

• Study Start (Actual): January 23, 2017
• Primary Completion (Actual): July 21, 2021
• Study Completion (Actual): July 21, 2021

Study Registration Dates

• First Submitted: November 15, 2016
• First Submitted That Met QC Criteria: December 5, 2016
• First Posted (Estimated): December 6, 2016

Study Record Updates

• Last Update Posted (Actual): April 21, 2026
• Last Update Submitted That Met QC Criteria: March 31, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Mental Disorders; Substance-Related Disorders; Chemically-Induced Disorders; Drinking Behavior; Behavior; Alcohol Drinking; Marijuana Abuse; 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: 1511001372; R01AA024091 (U.S. NIH Grant/Contract)

Drug and device information, study documents

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