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Vilazodone Treatment for Marijuana Dependence

This study has been completed.
National Institute on Drug Abuse (NIDA)
Information provided by (Responsible Party):
Aimee McRae-Clark, Medical University of South Carolina Identifier:
First received: April 5, 2012
Last updated: July 8, 2016
Last verified: July 2016
Marijuana is the most commonly used illicit drug, yet few clinical trials have evaluated pharmacotherapy treatments for marijuana dependence. This study will evaluate the efficacy of vilazodone for reducing marijuana use in marijuana-dependent adults. A contingency management intervention (CM)and motivational enhancement therapy (MET)will be incorporated to encourage study engagement and retention, and genomic DNA will be extracted to characterize subjects according to polymorphisms of genes potentially relevant to the activity of vilazodone. It is hypothesized that vilazodone combined with MET and CM will reduce the percent of marijuana-positive urine drug screen results in marijuana-dependent individuals as compared to a placebo treatment combined with MET and CM.

Condition Intervention Phase
Marijuana Dependence
Drug: Vilazodone
Drug: Placebo
Phase 2

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double Blind (Participant, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: Vilazodone Treatment for Marijuana Dependence

Resource links provided by NLM:

Further study details as provided by Medical University of South Carolina:

Primary Outcome Measures:
  • Percent Marijuana-negative Urine Drug Screens (UDS) [ Time Frame: 8 weeks ]
    Participants submitted a urine sample weekly. Percentage of marijuana negative urine samples were calculated per group.

Secondary Outcome Measures:
  • Weekly Cannabis Use Sessions [ Time Frame: 8 weeks ]
    Self-report of weekly cannabis use sessions was measured using the Time Line Followback, a calendar-based instrument designed to assess substance consumption.

  • Marijuana Craving and Withdrawal [ Time Frame: 8 weeks ]
    The Marijuana Craving Questionnaire (MCQ) is intended to measure marijuana craving in adults. It measures symptoms on four subscales: expectancy, purposefulness, emotionality, and compulsivity. The scale rates individual items from 1 (least craving) - 7 (most craving) with a composite scoring range of 12-84 and possible subscale scoring range of 3-21. It was administered weekly to all participants. Reported here is the mean MCQ purposefulness subscale score across 8 weeks.

Enrollment: 76
Study Start Date: August 2012
Study Completion Date: February 2016
Primary Completion Date: August 2015 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Vilazodone
Flexible dose up to 40 mg capsule daily
Drug: Vilazodone
up to 40 mg capsule daily
Other Name: Viibryd
Placebo Comparator: Placebo
Flexible dose up to 40 mg capsule daily
Drug: Placebo
up to 40 mg capsule daily

Detailed Description:

The purpose of this study is to determine if the medication vilazodone is effective in helping frequent marijuana smokers cut down or stop using marijuana. Vilazodone is FDA approved for the treatment of depression- in this study, vilazodone's effect on marijuana dependence is being investigated.

Participation in the study takes 10 visits over a period of approximately two to three months. The first visit is a screening visit to determine if participants are eligible to participate. After the initial assessment visit, the weekly visits take about 30 minutes, with the exception of three therapy sessions which take approximately 60-90 minutes. The three therapy sessions will focus on participant's marijuana use and reasons they may have for stopping or cutting down on use. After completing an initial therapy session, participants will be randomly selected to receive the study medication, either vilazodone or placebo (a capsule that does not contain any active medication). Participants will have weekly study visits with a clinician. At each study visit, they will be asked to fill out forms and answer specific questions concerning their substance use, anxiety symptoms, and feelings in general. They will be providing urine samples to check for illegal drugs of abuse including marijuana and other drugs. They will also have blood samples drawn during to determine if you are taking the medication as directed.


Ages Eligible for Study:   18 Years to 65 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Must meet DSM-IV criteria for marijuana dependence
  • Must be between the ages of 18 and 65 years old
  • If female and of childbearing potential, must agree to use acceptable method of birth control for duration of the trial.
  • Cannabis-positive urine drug screen at screening
  • Must consent to random assignment
  • Must be able to read and provide informed consent

Exclusion Criteria:

  • Women who are pregnant, nursing, or plan to become pregnant during course of study
  • Must not have a history of or current psychotic disorder, bipolar disorder, or eating disorder
  • Must not pose a current suicidal or homicidal risk
  • Must not have evidence or history of serious medical disease
  • Must not require concomitant therapy with psychotropic medication or CYP3A4 inhibitors
  • Must not be currently dependent on other substances, with the exception of nicotine;
  • Patients who, in the investigator's opinion, would be unable to comply with study procedures or assessments
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT01574183

United States, South Carolina
Medical University of South Carolina
Charleston, South Carolina, United States, 29425
Sponsors and Collaborators
Medical University of South Carolina
National Institute on Drug Abuse (NIDA)
Principal Investigator: Aimee L McRae-Clark, PharmD, BCPP Medical University of South Carolina
  More Information

Responsible Party: Aimee McRae-Clark, Associate Professor, Medical University of South Carolina Identifier: NCT01574183     History of Changes
Other Study ID Numbers: 16488
R21DA034089 ( US NIH Grant/Contract Award Number )
Study First Received: April 5, 2012
Results First Received: September 21, 2015
Last Updated: July 8, 2016

Keywords provided by Medical University of South Carolina:
Contingency management
Motivational enhancement therapy

Additional relevant MeSH terms:
Marijuana Abuse
Substance-Related Disorders
Chemically-Induced Disorders
Mental Disorders
Vilazodone Hydrochloride
Antidepressive Agents
Psychotropic Drugs
Serotonin Uptake Inhibitors
Neurotransmitter Uptake Inhibitors
Membrane Transport Modulators
Molecular Mechanisms of Pharmacological Action
Neurotransmitter Agents
Serotonin Agents
Physiological Effects of Drugs
Serotonin 5-HT1 Receptor Agonists
Serotonin Receptor Agonists processed this record on April 28, 2017