The aim of this study is evaluate the efficacy of Imipramine, a tricyclic antidepressant, in treatment of functional dyspepsia. This is a double blind randomised placebo controlled trial in which consecutive patients with diagnosis of functional dyspepsia will be studied. After exclusion of organic cause of dyspepsia by endoscopy, these patients will be randomly assigned to either imipramine or placebo. All the patients will enter an additional 4 weeks of drug withdrawal phase after the initial 12 weeks of study drug treatment. They will be evaluated for treatment response, which is defined as satisfactory relief of dyspeptic symptoms at the end of 12-week treatment.