Vilazodone Treatment for Marijuana Dependence

This study is ongoing, but not recruiting participants.
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 24, 2015
Last verified: July 2015
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
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, 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-positive urine drug screens [ Time Frame: 8 weeks ] [ Designated as safety issue: No ]
    The primary outcome for this study is the proportion of urine drug screens positive for marijuana.

Secondary Outcome Measures:
  • Time to first negative urine drug screen [ Time Frame: 8 weeks ] [ Designated as safety issue: No ]
    Secondary efficacy endpoint is time to first negative (passed) urine screen.

  • Percent of marijuana-positive self-reported days [ Time Frame: 8 weeks ] [ Designated as safety issue: No ]
    Secondary efficacy endpoint is percentage of marijuana-positive self-reported days

  • Study retention [ Time Frame: 8 weeks ] [ Designated as safety issue: No ]
    Secondary efficacy endpoint is retention in the study.

  • Marijuana craving and withdrawal [ Time Frame: 8 weeks ] [ Designated as safety issue: No ]
    Secondary endpoint of marijuana craving and withdrawal

Estimated Enrollment: 76
Study Start Date: August 2012
Estimated Study Completion Date: March 2016
Estimated Primary Completion Date: December 2015 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Vilazodone
40 mg capsule daily
Drug: Vilazodone
40 mg capsule daily
Other Name: Viibryd
Placebo Comparator: Placebo
40 mg capsule daily
Drug: Placebo
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
Genders Eligible for Study:   Both
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 meet criteria for current major depressive or generalized anxiety 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

No publications provided

Responsible Party: Aimee McRae-Clark, Associate Professor, Medical University of South Carolina Identifier: NCT01574183     History of Changes
Other Study ID Numbers: 16488, R21DA034089
Study First Received: April 5, 2012
Last Updated: July 24, 2015
Health Authority: United States: Food and Drug Administration

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

Additional relevant MeSH terms:
Marijuana Abuse
Chemically-Induced Disorders
Mental Disorders
Substance-Related Disorders processed this record on November 27, 2015