Brain Imaging of Cocaine Craving in Recreational Cocaine Users

Chronic cocaine exposure is associated with an intensified and broadened pattern of neural
reactivity to cocaine and cocaine cues; prolonged use is also associated with prefrontal
abnormalities during response inhibition. Limited research suggests that recreational
cocaine use has similar, but attenuated, effects on neural functioning. Unfortunately, very
little research has directly compared cocaine dependent individuals and recreational cocaine
users in terms of their neural reactivity to cocaine cues and response inhibition. Such
comparisons could help to elucidate the pathological neuroplasticity associated with the
transition from cocaine use to dependence. The proposed study will assess neural reactivity
to cocaine cues and response inhibition in recreational cocaine users using fMRI. These data
will be compared to data from the baseline visit of an ongoing IRB approved investigation
(NCT00759473) in cocaine dependent individuals that is using the same experimental
procedures as the proposed study.

Inclusion Criteria:

- Subjects must be able to provide informed consent and function at an intellectual
level sufficient to allow accurate completion of all assessment instruments.

- Subjects must report having used cocaine within the past 3 months. Subjects may meet
criteria for abuse, but not dependence on any other substance with the exception of
nicotine, marijuana and alcohol.

- Use of one of the following methods of birth control by female subjects: birth
control pills, barrier methods (diaphragm or condoms with spermicide or both),
surgical sterilization, use of an intra-uterine contraceptive device, or complete
abstinence from sexual intercourse.

- Subjects must live within a 50-mile radius of the research facility and have reliable
transportation.

- Subjects must consent to remain abstinent from all drugs of abuse (except nicotine)
prior to the experiment.

- Subjects must be right-handed.

Exclusion Criteria:

- Women who are pregnant, nursing or of childbearing potential and not practicing an
effective means of birth control.

- Subjects with evidence of or a history of significant hematological, endocrine,
cardiovascular, pulmonary, renal, gastrointestinal, or neurological disease including
diabetes, as these conditions may affect heart rate or skin conductance measurement.

- Subjects with a history of or current psychotic disorder as this may impact cue
reactivity.

- Subjects who are unwilling or unable to maintain abstinence from alcohol and other
drugs of abuse (except nicotine).

- Subjects meeting DSM-IV criteria for substance dependence (other than nicotine,
marijuana, or alcohol) within the past 60 days. Subjects may not meet criteria for
cocaine dependence at any time.

- Subjects currently taking B-blockers, anti-arrhythmic agents, psychostimulants or any
other agents known to interfere with heart rate and skin conductance monitoring.

- Subjects with a history of epilepsy or seizure disorder.

- Subjects with significant liver impairment.

- The need for maintenance or acute treatment with any psychoactive medication
including anti-seizure medications which could potentially interfere with fMRI.

- Clinically significant psychiatric or medical problems that would impair
participation or limit ability to participate in scan.

- Persons with ferrous metal implants or pacemaker since fMRI will be used.