PRIOR CONCURRENT THERAPY: Biologic therapy: Not specified Chemotherapy: Not specified Endocrine therapy: More than 30 days since prior systemic steroids Radiotherapy: Not specified Surgery: Not specified Other: More than 30 days since other prior behavioral or pharmacologic smoking- cessation program (e.g., behavioral therapy, nicotine replacement therapy, clonidine, bupropion, nortriptyline, or doxepin) More than 30 days since prior investigational drugs More than 30 days since prior antipsychotics or antidepressants More than 30 days since prior theophylline More than 30 days since prior monoamine oxidase inhibitor More than 30 days since prior medication containing bupropion No concurrent antiepileptic medications No concurrent medications known to lower seizure threshold No other concurrent investigational drugs