 Subjects will be excluded if they have: 1 an unstable medical condition; 2 unstable angina, myocardial infarction, or coronary angioplasty within the past 3 months or an untreated cardiac dysrhythmia; 3 personal history of seizures; 4 closed head trauma with any loss of consciousness or amnesia in the last 5 years; 5 ever history of closed head trauma with 30 minutes of loss of consciousness or amnesia or resulting in skull fracture or subdural hematomabrain contusion; 6 a history or psychosis, bipolar disorder, bulimia or anorexia nervosa; 7 have current depression as assessed by Center for Epidemiologic Studies Depression CES-D; 8 have active substance abuse other than nicotine; 9 have used an investigational drug within the last 30 days; 10 are currently using a behavioral or pharmacologic tobacco treatment and unwilling or unable to discontinue use; 11 use of bupropion or varenicline in the previous 3 months; 12 current past 14 days use of antipsychotic or antidepressant; 13 an allergy to bupropion or varenicline; 14 untreated hypertension or baseline systolic blood pressure 180 or diastolic 100; 15 have another member of their household already participating in this study. 