The goal of this study is to use [C-11]FLB 457 and amphetamine (oral, 0.5 mg/kg) to measure cortical dopamine transmission in cocaine dependent individuals and healthy controls

This study seeks to examine dopamine (DA) transmission in vivo, using positron emission tomography (PET) with [C-11]FLB 457, in cortical regions of interest in subjects who have a history of cocaine dependence. We hypothesize that cocaine dependence is associated with decreases in dopamine in the prefrontal cortical regions compared to controls. This may explain the impulsivity and cognitive deficits that underlie relapse in this disorder.

Subjects with Cocaine Dependence INCLUSION CRITERIA

1. Males or Females 18-40
2. Fulfill Diagnostic and Statistical Manual (DSM-IV) Diagnosis for Cocaine Dependence
3. Medically Healthy MAJOR EXCLUSIONS

1. Major medical, psychiatric, co-morbid drug & alcohol use disorders 2. Pregnancy or lactation, 3. Contraindications to MRI 4. Currently employed as radiation worker; or participation in radioactive drug research protocols within the previous year 5. Family History of a psychotic illness or manic episode in first-degree relatives

Healthy Subjects INCLUSION CRITERIA

1. Males or Females 18-40
2. Absence of present or past psychiatric conditions (including alcohol or drug dependence)
3. A negative urine drug screen
4. Medically Healthy

MAJOR EXCLUSIONS

1. Any medical, psychiatric, co-morbid drug & alcohol use disorders
2. Pregnancy or lactation,
3. Contraindications to MRI
4. Currently employed as radiation worker; or participation in radioactive drug research protocols within the previous year
5. Family History of a psychotic illness or manic episode, or drug and alcohol Abuse/Dependence in first-degree relatives