Cannabis Dependence | Quetiapine Pharmacotherapy for Cannabis Dependence

Cannabis Dependence research study

What is the primary objective of this study?

Despite a benign public perception, marijuana use disorders represent a significant public health problem. The development of safe and effective pharmacotherapies for marijuana dependence is an important unmet public health need. Quetiapine, an effective atypical antipsychotic that acts by blocking serotonin type 2A, dopamine type 2, histamine type 1, and adrenergic receptors, is a promising treatment for substance use disorders. In animal models, quetiapine blocks the enhancement of reward by cocaine, which is likely due to its actions on both dopamine and non-dopamine neurotransmission. Clinical studies of quetiapine have shown benefit for the treatment of alcohol and cocaine use disorders. Conceptually, the clinically prominent effects of quetiapine, namely sedation, anxiolysis, mood stabilization and appetite stimulation, are a good match for the symptoms of marijuana withdrawal. Most importantly, an open-label dose-finding study of quetiapine for the treatment of marijuana dependence conducted by our research group determined that quetiapine was well-tolerated and associated with reductions in marijuana use indicating that it is a promising agent deserving of further study in marijuana-dependent outpatients. The proposed research project is a randomized double-blind placebo-controlled clinical trial to evaluate the efficacy of quetiapine for the treatment of marijuana dependence over a 12-week period. All participants will receive Medical Management, a medication adherence focused psychosocial intervention that facilitates compliance with study medication and other study procedures, promotes abstinence from marijuana and other substances, and encourages mutual-support group attendance. All participants will receive voucher incentives for compliance with study visit attendance, returning study medication bottles, and completing other study procedures, with the objective of achieving a highly compliant sample. The goal of this phase II clinical trial is to build on our promising open-label pilot study results and examine the efficacy of quetiapine on participants' marijuana consumption under placebo-controlled double-blind conditions using an abstinence-initiation model, where participants will be using marijuana regularly at study entry, reduce their use, and then achieve abstinence. The specific aims of the projects are to determine whether quetiapine is superior to placebo in 1) reducing marijuana use and 2) achieving abstinence.

Who is eligible to participate?

Inclusion Criteria: 1. Meets DSM-IV-TR criteria for current marijuana dependence 2. Reports using marijuana an average of 5 days per week over the past 28 days 3. Between the ages of 18 and 60 4. Able to provide informed consent and comply with study procedures 5. Seeking treatment for cannabis dependence Exclusion Criteria: 1. Lifetime DSM-IV diagnosis of schizophrenia, schizoaffective disorder, or bipolar disorder. 2. Current DSM-IV criteria for any other psychiatric disorder that may, according to investigator's judgment, require either pharmacological or non-pharmacological intervention over the course of the study. 3. Patients prescribed psychotropic medications. 4. History of allergic reaction, intolerance, or hypersensitivity to Quetiapine. 5. Pregnancy, lactation, or failure to use adequate contraceptive methods in female patients who are currently engaging in sexual activity with men. 6. Unstable medical conditions, such as poorly controlled hypertension which might make participation hazardous. 7. Diabetes (whether controlled or not), meeting criteria for metabolic syndrome as defined by the NCEP (any 3 of the following: a. obesity [waist circumference > 40 inches], b. hyperglycemia [fasting glucose > 100 mg/dl or Rx], c. dyslipidemia [TG > 150 mg/dl or Rx], d. dyslipidemia [HDL cholesterol; 40 mg/dl (male), 50 mg/dl (female) or Rx], e. hypertension [130 mmHg systolic or > 85 mmHg diastolic or Rx]. Participants with a BMI > 35 will be excluded. 8. Current DSM-IV diagnosis of an alcohol or substance use disorder (abuse or dependence) other than marijuana or nicotine dependence. 9. Positive confirmed result on urine toxicology screen. 10. Are legally mandated to participate in a substance use disorder treatment program. 11. Increased risk for suicide. 12. QTc prolongation (screening electrocardiogram with Qtc > 450 msec for men, QTc > 470 msec for women) or history of QTc prolongation or using concomitant medications which prolong QTc interval.

Which medical condition, disease, disorder, syndrome, illness, or injury is researched?

Cannabis Dependence

Study Interventions

Interventions can include giving participants drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available or noninvasive approaches such as surveys, education, and interviews.

Drug:QuetiapineQuetiapine pharmacotherapy for cannabis dependence

Drug:Placeboplacebo capsules

Study Arms

Research studies and clinical trials typically have two or more research arms. An arm is a group of people who receive the same treatment in the study.

PlaceboPlacebo medication

quetiapineQuetiapine treatment

Study Status


Start Date: October 1, 2012

Completed Date: April 30, 2017

Phase: Phase 2

Type: Interventional


Primary Outcome: Marijuana Use, Daily Dollar Averaged Over 7 Days During Each of 12 Weeks of Study

Secondary Outcome:

Study sponsors, principal investigator, and references

Principal Investigator: John J Mariani, MD

Lead Sponsor: New York State Psychiatric Institute

Collaborator: National Institute on Drug Abuse (NIDA)

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