Participants will be randomly assigned to receive either bupropion or placebo. Study visits will occur after one-week treatment with placebo or bupropion. During study sessions, participants will come to the laboratory at 9 am and will remain abstinent in the laboratory for 5 hrs. Participants will then be assessed for craving and withdrawal symptoms after viewing and handling neutral cues and smoking cues. After that, participants will have a 90-min period to smoke, and smoking topography will be measured.