This trial is active, not recruiting.

Condition marijuana dependence
Treatments vilazodone, placebo
Phase phase 2
Sponsor Medical University of South Carolina
Collaborator National Institute on Drug Abuse (NIDA)
Start date August 2012
End date December 2015
Trial size 76 participants
Trial identifier NCT01574183, 16488, R21DA034089


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.

United States No locations recruiting
Other Countries No locations recruiting

Study Design

Allocation randomized
Endpoint classification safety/efficacy study
Intervention model parallel assignment
Masking double blind (subject, investigator, outcomes assessor)
Primary purpose treatment
40 mg capsule daily
vilazodone Viibryd
40 mg capsule daily
(Placebo Comparator)
40 mg capsule daily
placebo Placebo
40 mg capsule daily

Primary Outcomes

Percent marijuana-positive urine drug screens
time frame: 8 weeks

Secondary Outcomes

Time to first negative urine drug screen
time frame: 8 weeks
Percent of marijuana-positive self-reported days
time frame: 8 weeks
Study retention
time frame: 8 weeks
Marijuana craving and withdrawal
time frame: 8 weeks

Eligibility Criteria

Male or female participants from 18 years up to 65 years old.

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

Additional Information

Official title Vilazodone Treatment for Marijuana Dependence
Principal investigator Aimee L McRae-Clark, PharmD, BCPP
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.
Trial information was received from ClinicalTrials.gov and was last updated in July 2015.
Information provided to ClinicalTrials.gov by Medical University of South Carolina.