The normal control subjects will be randomized to receive either amitriptyline or desipramine as the tricyclic antidepressant agent, with 30 subjects per group. Subjects will undergo two outpatient gastric emptying/volume tests and two satiety tests; one of each after 7 days of treatment with oral consumption of the study agent and the other one of each after 7 days of treatment with placebo. The order of the treatments (active drug or placebo) will be randomized with 7 days washout between the studies. During the study, the subjects will consume their regular diet. Subjects will also be randomized to receive either amitriptyline 25 mg po qhs as the active drug or desipramine 25 mg po qhs as the active drug. Side effects of the agents will be monitored during the study.