Brain Nicotine Receptor Density & Response to Nicotine Patch

Inclusion Criteria: * Healthy adult who is a tobacco dependent smoker (smokes 10-30 cigarettes per day) meeting criteria for Nicotine Dependence as defined by DSM-IV criteria * Has the desire to quit smoking * Ability to read, write, and give voluntary informed consent * An exhaled CO greater than or equal to 8 ppm during the study screening visit to verify smoking status Exclusion Criteria: * Any history of an Axis I psychiatric diagnosis other than Nicotine Dependence (including other substance abuse/dependence and mood, anxiety, and psychotic disorders) * Any current medication or any history of a medical condition that might affect the central nervous system at the time of scanning (e.g., current treatment with a psychotropic medication, or history of severe head trauma or epilepsy). * Unstable cardiovascular disease, liver disease, or renal insufficiency. Routine history and physical examination will be performed at the initial screening visit to insure that participants meet study criteria * Pregnancy (urine pregnancy tests will be obtained on all women of child-bearing potential) due to the theoretical risk of radiation exposure to the fetus. Pre-menopausal women will only be scanned during the early follicular phase (by participant report) of the menstrual cycle because hormonal levels have been shown to affect nicotine metabolism. * Caffeine dependence, as evidenced by withdrawal symptoms temporally associated with caffeine ingestion.