Quetiapine for the Reduction of Cocaine Use

Inclusion Criteria: 1. Provision of written informed consent 2. Males and females aged 18-65 years 3. Female subjects of childbearing potential must be using a reliable method of contraception and have a negative urine human chorionic gonadotropin (HCG) test at the screening and baseline visits and agree to use one of the following methods of birth control: a) oral contraceptive, b) patch, c) intrauterine progesterone or non-hormonal contraceptive system, d) levonorgestrel implant, e) medroxyprogesterone acetate contraceptive injection, or f) complete abstinence from sexual intercourse 4. A diagnosis of current cocaine dependence; as determined by the Structured Clinical Interview for DSM-IV-TR Axis I Disorders 69 (SCID-I/P) 5. Has used cocaine within the 30 days prior to screening 6. Able to understand and comply with the requirements of the study 7. Is seeking treatment for cocaine dependence 8. Is able to provide a reliable primary contact phone number and is able to provide a reliable alternate contact address and phone number, such as for a relative or close friend 9. Anticipates no life changes that would preclude study completion Exclusion Criteria: 1. Pregnancy or lactation 2. Currently hospitalized or in a detoxification program 3. Physiological dependence on alcohol, sedative/hypnotic, or any other substance requiring medical detoxification 4. Current diagnosis of psychotic disorder, including bipolar disorder with psychotic features, as determined by the SCID-I/P or clinical interview 5. Subjects who are judged by the investigator to be psychiatrically unstable, including posing an imminent risk of suicide or a danger to self or others, as determined by the SCID-I/P, CGI-S, Hamilton Anxiety Rating Scale(HAM-A), Hamilton Rating Scale for Depression(HAM-D), or clinical interview 6. Known intolerance or lack of response to quetiapine fumarate, as judged by the investigator 7. Has a history of neuroleptic malignant syndrome or other serious adverse reaction to antipsychotic medication 8. Use of any antipsychotic medication within the 30 days preceding baseline 9. Use of any of the following cytochrome P450 3A4 inhibitors in the 14 days prior to baseline including but not limited to: ketoconazole, itraconazole, fluconazole, erythromycin, clarithromycin, troleandomycin, indinavir, nelfinavir, ritonavir, fluoxetine, fluvoxamine, paroxetine, and saquinavir 10. Use of any of the following cytochrome P450 inducers in the 14 days prior to baseline including but not limited to: phenytoin, carbamazepine, barbiturates, rifampin, St. John's Wort, and glucocorticoids 11. Evidence of any clinically relevant disease (e.g., renal, hepatic, gastrointestinal, pulmonary, cardiac, or cerebrovascular disease, AIDS, cancer, asthma, neurological or neuromuscular disease, seizure disorder, or clinically significant abnormal laboratory value) or any clinical finding that in the judgment of the investigator could potentially be negatively affected by study participation or that could potentially affect study participation