Effect of fluoxetine on symptoms and gastric dysrhythmia in patients with functional dyspepsia

Background/Aims: Although antidepressants have been used for decades in treating patients with functional abdominal syndromes, how they influence gastrointestinal motility remains unclear. We aimed to assess the role of depression in functional dyspepsia, and the effect of antidepressants on the functional dyspepsia patients' symptoms and gastric myoelectrical activity. Methodology: We conducted an open clinical trial with 40 functional dyspepsia patients. Zung self-rating depression scale was used in evaluating the patients' depression. Cutaneous electrogastrography and evaluation of upper gastrointestinal symptoms were performed before and after administration of a one-month course of fluoxetine. Results: In the baseline study, the depressed functional dyspepsia patients had higher symptom scores than non-depressed patients (P<0.05). The depressed functional dyspepsia patients had higher percentages of tachygastria than healthy controls (P<0.05), but the electrogastrography parameters of depressed and non-depressed functional dyspepsia patients were not different. After one-month fluoxetine treatment, the symptom scores improved significantly in the depressed functional dyspepsia patients (P<0.05), but not in the non-depressed patients. Electrogastrography did not improve in either group. Conclusions: Depressive functional dyspepsia patients had higher symptom scores and responded well to fluoxetine treatment. However, electrogastrography did not improve after the treatment. These findings suggest that depression is significant in the presentation of functional dyspepsia symptoms, but not correlated with gastric myoelectrical activity.