Effect of Quetiapine on Marijuana Withdrawal and Relapse

• Marijuana relapse [ Designated as safety issue: No ]
• Marijuana's direct effects [ Designated as safety issue: No ]
• Marijuana withdrawal symptoms [ Designated as safety issue: No ]

The objective of this study is to investigate the interaction between marijuana and quetiapine, with the goal of using this information to improve marijuana treatment outcome. It is hypothesized that quetiapine will decrease marijuana withdrawal and relapse. Primary outcome measures will be

1. marijuana's direct effects
2. marijuana withdrawal syndromes
3. marijuana relapse. It is also hypothesized that marijuana withdrawal will be associated with increased levels of stress hormones. A secondary measure will be salivary cortisol.

Quetiapine improves sleep and reduces anxiety and irritability, which are symptoms of marijuana withdrawal. Further, there are case reports showing that marijuana-dependent schizophrenics maintained on quetiapine had a 97.3% reduction in marijuana use. Thus, the purpose of this study is to determine if quetiapine decreases marijuana's direct effects, symptoms of marijuana withdrawal and marijuana relapse in the laboratory. The study will utilize and inpatient/outpatient, counter-balanced design, with each participant maintained on placebo and quetiapine (200 mg/day) for 18 days. Participants will begin taking capsules as outpatients so that the dose can be incremented prior to the inpatient phase. While inpatient, participants will have the opportunity to self-administer placebo or active marijuana 6 times per day. Our laboratory model, which has distinguished the effects of a range of medications on marijuana withdrawal and relapse, will provide important information on the effect of quetiapine as a potential short-term pharmacotherapy to facilitate abstinence in the initial stages of marijuana treatment.

• Drug: Marijuana
  0,6.9% THC
  Other Name: cannabis
• Drug: Quetiapine
  0, 200 mg/day
  Other Name: seroquel

Inclusion Criteria:

• Current marijuana use:average of 2 marijuana cigarettes per day at least 4 times per week for the past 4 weeks
• Able to perform study procedures
• 21-45 years of age
• Women practicing an effective form of birth control (condoms, diaphragm, birth control, pill, IUD)
• Normal body weight

Exclusion Criteria:

• Current, repeated illicit drug use (other than marijuana)
• Presence of significant medical illness (e.g., diabetes, cardiovascular disease, hypertension, clinically significant abnormalities)
• History of heart disease or current conduction system disease as indicated by QRS duration > 0.11
• Request for drug treatment
• Current parole or probation
• Pregnancy or current lactation
• Recent history of significant violent behavior
• Major current Axis I psychopathology (major depressive disorder, bipolar disorder, suicide risk, schizophrenia)
• Current use of any prescription or over-the-counter medication
• Prior allergic or otherwise serious adverse reaction to quetiapine

• Research Foundation for Mental Hygiene
• National Institute on Drug Abuse (NIDA)