Clinical Research Directory

Inclusion Criteria: * 25 years of age and older * Score of at least 3 on the Severity of Dependence Scale * Desire to cease cocaine use as indicated by a goal of complete cocaine abstinence on the Thoughts about Abstinence questionnaire * Ability to read/write in English * No prior hallucinogen use or it will have been at least 3 years since their last use of a hallucinogen * Availability of a friend or family member into whose care the participant can be released following their drug administration session. * In good general health as assessed by detailed medical history and physical examination * Abstinence from cocaine for at least 7 days prior to experimental drug administration as confirmed via urinalysis and no signs of intoxication on other drugs. Exclusion Criteria: * 24 years of age and younger * Women who are pregnant or breast feeding * Current psychiatric diagnoses other than substance abuse/dependence * Current hypertension (exceeding 140 systolic and 90 diastolic at resting as described below) * Use of tricyclic antidepressants, lithium, Selective Serotonin Reuptake Inhibitors, Monoamine Oxidase Inhibitors, haloperidol, St. John's Wort, or other antipsychotic medications, mood stabilizers, or medications with serotonin activity * History of any psychotic disorders * History of bipolar I or II disorder * First or second-degree relatives with any psychotic disorders, or bipolar I or II disorders * Current suicidal or homicidal ideation * Planning to move from the Birmingham area in the next 6 months * Contraindications of MRI (metallic objects in the body, claustrophobia, difficulty with prior MRI)