PROJECT SUMMARY / ABSTRACT African Americans are disproportionality burdened by tobacco in the United States. African American smokers experience the highest rates of tobacco-attributable disease, cancer incidence and mortality. Striking health disparities exist despite the fact that African Americans have similar smoking prevalence as Whites, yet smoke fewer cigarettes per day (cpd). To have an impact on the premature mortality of African American smokers, effective treatment for smokers across the smoking continuum must be identified. Further, because smoking cessation rates tend to be lower for African American smokers, it is necessary to find methods of increasing response to pharmacotherapy to better promote abstinence in this high-risk group. Extended treatment has been demonstrated to increase abstinence in White smokers but has never been examined in African American smokers, who might benefit from extended medication support for quitting and for reducing relapse. The primary objective of this study is to evaluate extended use of varenicline, the leading FDA-approved medication for tobacco treatment, with the goal of enhancing abstinence in African American daily smokers, including the full spectrum of light, moderate, and heavy smokers. Our specific aims are to 1) evaluate the efficacy of extended varenicline treatment to promote smoking cessation at end of treatment (Month 6) and at long-term follow-up (Months 9 and 12), 2) examine medication adherence over the course of treatment and its impact on treatment outcomes, 3) evaluate change in negative affect, withdrawal, and craving across treatment conditions and their impact on treatment outcomes, 4) identify individual factors predicting smoking abstinence, and 5) characterize patterns of tobacco use and abstinence over the course of standard and extended treatment. These aims will be accomplished using a two-arm, randomized design to evaluate the efficacy of extended (6 months) varenicline treatment compared to standard (12 weeks) varenicline treatment. Baseline randomization stratified by gender will assign participants (N=500) to receive extended treatment (EXT; 26 weeks of varenicline, n=250) or standard treatment (ST; 12 weeks of varenicline, n=250). All participants will receive culturally-relevant, individualized smoking cessation counseling, including support for medication adherence, and will be followed through Month 12. This study is the first to examine the efficacy of extended varenicline treatment to increase abstinence among African American smokers, including the full spectrum of daily smoking level. It is the first to examine extended varenicline for all smokers, not only confirmed quitters, and among the first to examine patterns of quitting, lapse, and relapse among African American smokers. Findings will enrich our understanding of the interrelationship of key biological factors to smoking factors and treatment response. Success in increasing long-term abstinence rat...