 Patients with bipolar disorder have one of the highest rates of nicotine dependence and one of the lowest quit rates. Varenicline has been shown in previous trials to be effective for smoking cessation, but has not been studied in subjects with bipolar disorder. This 12-week open label trial will be conducted to assess the feasibility, acceptability, and safety of varenicline in bipolar depressed smokers, given in addition to the subjects primary treatment for bipolar disorder. The primary study hypothesis was that the abstinence rate for bipolar depressed patients will be 50. 