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

Drug: Marijuana
0,6.9% THC
Drug: Quetiapine
0, 200 mg/day

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.