Plasma 5-hydroxytryptamine concentration and its correlation with psychopathology in patients with irritable bowel syndrome.

BACKGROUND/AIMS: Irritable bowel syndrome (IBS) is a biopsychosocial disorder. 5-Hydroxytryptamine (5-HT) plays a crucial role in the control of gastrointestinal motility, sensation, and secretion. This study investigated changes in platelet-depleted plasma 5-HT and their correlation with psychopathology in IBS patients and healthy subjects.
METHODS: This study involved 21 subjects with IBS and 13 healthy subjects. Fasting and 1-hr postprandial plasma 5-HT concentrations were measured. The SCL-90R symptom checklist was used for the assessment of current psychological symptoms.
RESULTS: Fasting and postprandial plasma 5-HT concentrations were significantly higher in IBS patients (15.11+/-13.51 ng/mL and 16.31+/-14.21 ng/mL, respectively) than in healthy subjects (5.55+/-4.14 ng/mL and 6.25+/-4.82 ng/mL, respectively; p<0.05). There were no significant changes between fasting and 1-hr postprandial 5-HT concentration in IBS subtypes and healthy subjects. Scores on all SCL-90R subscales except for the interpersonal-sensitivity subscale were significantly higher in IBS patients than in healthy subjects. No correlation was found between SCL-90R items and platelet-depleted plasma 5-HT concentration.
CONCLUSIONS: 5-HT might play a critical role in IBS, and psychopathological factors are correlated with IBS.