The purpose of this study is to assess neurocognitive and associated neural regions/circuitry disruptions relevant to impulsive relapse in cocaine-addicted subjects, and the relationship of the cognitive and neural mechanisms of impulsivity/decision-making to relapse style.

This study is designed to explore putative differences in impulsive behaviors and decision making in cocaine-addicted and healthy control subjects using functional magnetic resonance imaging (fMRI), single photon emission tomography (SPECT), and neurocognitive tasks. We predict that cocaine-addicted subjects will demonstrate neurocognitive and neural alterations in measures of impulsivity and decision-making when compared to healthy controls. That is, cocaine-addicted subjects will show both decreased activation and decreased resting measures of regional cerebral blood flow (rCBF) of the brain structures associated with impulsivity and decision-making. Furthermore, neurocognitive and neural deficits associated with impulsivity and decision-making will be associated with each other and with measures indicative of an impulsive relapse and altered decision making.

Inclusion Criteria:

• Cocaine-dependence (patient population) or no cocaine-dependence (control population).

Exclusion Criteria:

• Other medical or psychiatric disorders that may effect neural functioning.
• Medications that may effect neural functioning.

Patients will be recruited from residential treatment programs at the VA North Texas Health Care System, Nexus Recovery Inc., and Homeward Bound Inc. Healthy controls will be recruited from the Greater Dallas community.