This is a clinical research protocol to study the efficacy of combined varenicline (Chantix) and motivational interviewing (MI) for smoking cessation in a sample of smokers who have been diagnosed with schizophrenia or schizoaffective disorder. The study is a double-blind, randomized, controlled, subacute treatment trial of MI plus varenicline (VAR-MI) versus MI plus placebo (PLA-MI). The pharmaceutical treatment will utilize Chantix at a dose of 1 mg/day for a period of two weeks.