Functional dyspepsia is a common gastrointestinal disorder. Symptoms can include stomach pain or discomfort, bloating, fullness after eating meals, and nausea. These symptoms often interfere with school and work, and weight loss may occur due to dietary restrictions.

The hypothesis of this study was that antidepressant therapy is more effective than placebo in relief of the symptoms of functional dyspepsia, adjusting for psychological and psychiatric co-morbidity. The study also examined if antidepressant therapy reduces disability and improves quality of life in functional dyspepsia.

The aims of this study were to:

1. Determine whether antidepressant therapy is more efficacious than placebo in relief of the symptoms of functional dyspepsia, adjusting for psychological and psychiatric co-morbidity. The investigators also planned to determine if antidepressant therapy reduces disability, improves quality of life and influences clinical response over 6 months after ceasing medication.
2. Determine if gastric emptying (motor dysfunction) and the nutrient drink test (a test that assesses gastric hypersensitivity and/or gastric accommodation) is altered by antidepressant therapy with a tricyclic or selective serotonin re-uptake inhibitors (SSRI), and whether subgroups with altered physiology are associated with treatment outcome.

Inclusion Criteria:

• Normal esophagogastroduodenoscopy (EGD) (no esophagitis, Barrett's esophagus, cancer, erosions, or ulcer disease) within the past 5 years
• Diagnosis of functional dyspepsia
• Patients may have failed to adequately respond to antisecretory therapy in the past for functional dyspepsia to be suitable; a good response to antisecretory therapy, which remains first line therapy, suggests underlying gastroesophageal reflux disease (GERD).

Exclusion Criteria:

• Any documented history of endoscopic esophagitis, or predominant heartburn or acid regurgitation, or these symptoms two or more times per week in the prior year, to exclude GERD.
• Those who have had an adequate response to antisecretory therapy according to the physician interview, to exclude patients with disease easy to control with first line therapy or misdiagnosed GERD.
• Any documented peptic ulcer disease.
• Regular use of non-steroidal anti-inflammatory drugs (except long term low dose aspirin ≤ 325 mg / day)
• Subjects undergoing psychiatric treatment, having a current history of drug or alcohol abuse, or currently taking psychotropic medication for depression or psychosis, or eating disorders
• A history of abdominal surgery except appendectomy, cholecystectomy or hysterectomy, tubal ligations, bladder slings, and vasectomies
• Subjects with concurrent major physical illness (including cardiac or liver disease, diabetes, inflammatory bowel disease, glaucoma, urinary retention, active thyroid disease, vasculitis, lactose intolerance explaining symptoms)
• Subjects whose literacy skills are insufficient to complete self report questionnaires.
• Pregnancy, or refusal to apply adequate contraceptive measures during the trial
• Subjects currently on antidepressant therapy will be excluded.
• Patients who score 11 or greater on the 7 questions related to depression of the Hospital Anxiety Depression Scale will be excluded. These patients will be encouraged to get follow up for depression.
• All eligible patients over age 50 will have an EKG before randomization. Those found to have significant arrhythmias, conduction defects or a previous myocardial infarction on EKG will be excluded. Anyone with QT prolongation will be excluded.

The following concomitant medications will be prohibited during the trial:

• Systemically acting cholinergics and anticholinergics (atropine, didinium bromide, propantheline)
• Prokinetics (e.g., metoclopramide, tegaserod)
• Macrolide antibiotics (e.g., erythromycin, azithromycin)
• Aspirin (> 325 mg/day)
• Spasmolytics (e.g., dicyclomine)
• Antidepressants other than study medications
• Serotonin enhancing drugs: monamine oxidase inhibitors, anticonvulsants, dextromethorphan.

Participants will be instructed to avoid grapefruit/grapefruit juice during the trial.