A sustained-release form of bupropion was effective for smoking cessation and was accompanied by reduced weight gain and minimal side effects. Many participants in all groups were smoking at one year.

In persons who stopped smoking with 7 weeks of bupropion treatment, sustained-release bupropion for 12 months delayed smoking relapse and resulted in less weight gain.

Bupropion is efficacious for smoking cessation independently of a former history of major depression or alcoholism. Increases in depressive symptoms during an initial period of abstinence are associated with a return to smoking.