Exclusion Criteria:

• Pregnant or nursing women, or women of child-bearing potential who are not using an adequate method of contraception
• Psychiatric illnesses requiring psychotropic medications (i.e., psychosis, major depression, mania), or the presence of suicidality or homocidality
• Current use of nicotine replacement therapies (i.e., nicotine patch, gum, or lozenges, nasal spray, or inhaler), bupropion (Zyban, Wellbutrin), or marijuana or current participation in another smoking cessation treatment
• Presence of unstable medical conditions (i.e., cardiac, hepatic, renal disease, diabetes mellitus) that would make a trial of bupropion SR hazardous
• Have taken monoamine oxidase inhibitors or metoprolol succinate within the past six weeks
• History of anorexia nervosa or bulimia
• Previous hypersensitivity to bupropion
• History of alcohol or other drug dependence in the past one year
• History of seizure disorder of any etiology (i.e., brain tumor, traumatic brain injury, substance-induced seizures, etc.)
• Any finding that in the view of the principal investigator would compromise the subject's ability to fulfill the protocol visit schedule and visit requirements or put the subject at risk
• Sharing home or work environment with current or past participant
• No couples or participants who see each other every day