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Completed

NCT Number: NCT02983773

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.

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Key information

Conditions

Alcohol Drinking Behavior Chemically-Induced Disorders Drinking Behavior Marijuana Marijuana Abuse Mental Disorders Substance-Related Disorders

Age range

21 year–44 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 2

Primary location

Brown University

Providence, Rhode Island, 02912, United States

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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)

Treatment and study plan

THC 7.2%

Drug

1 smoked marijuana cigarette with 7.2% THC

THC 3.1%

Drug

1 smoked marijuana cigarette with 3.0% THC

Placebo

Drug

1 smoked placebo marijuana cigarette

Primary outcomes

  1. Alcohol Craving

    Time frame: 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

    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.

Secondary outcomes

  1. Percent of Total Available Alcohol Consumed

    Time frame: post-smoking during two-hour alcohol choice task during the experimental session

    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.

Sponsors and collaborators

Lead sponsor

Brown University

Other

Collaborators

  • National Institute on Alcohol Abuse and Alcoholism (NIAAA)

Registry information

Important dates

Study start
2017
Primary completion
2021
Study completion
2021
First posted
Dec 6, 2016
Registry last updated
Apr 21, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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