<qa>  What is the name of the cause of disability and mortality worldwide?Tobacco use disorder and bipolar disorders are top of the causes of disability and mortality worldwide. The aim of this study was to evaluate N-acetyl-cysteine NAC as an adjunctive treatment in patients with Tobacco use disorder with comorbid bipolar disorder N72 NACplacebo recruited from outpatients smoking cessation unit at Londrina State University, Brazil. 