Varenicline in Bipolar Depressed Patients

Varenicline, a nicotinic acetylcholine receptor partial agonist, has been shown in two placebo-controlled trials to be efficacious for smoking cessation. Given the high prevalence of nicotine dependence in bipolar disorder and the high prevalence of sub-syndromal and syndromal depressive symptoms in bipolar disorder, this 12-week adjunctive varenicline open label trial will be conducted to assess the feasibility, acceptability, and safety of varenicline in bipolar depressed smokers. All subjects will receive individual behavioral counseling. Primary hypothesis: the abstinence rate for bipolar depressed patients will be 50%. Secondary hypothesis: At final visit, bipolar depressed patients who have achieved remission, defined as a Montgomery Asberg Depression Rating Scale (MADRS) \<8, will have a higher rate of tobacco abstinence than depressed patients who did not achieve remission (MADRS \>/= 8).