Prediction of treatment outcome of patients with functional gastrointestinal disorders by the Diagnostic Criteria for Psychosomatic Research

Background: The Diagnostic Criteria for Psychosomatic Research (DCPR) have been demonstrated to be useful in identifying specific psychological conditions of medical patients. The aim of this study was to evaluate the clinical utility of the DCPR in predicting the treatment outcome of patients with functional gastrointestinal disorders (FGID). Methods: FGID outpatients were allocated to improved (n = 65) and unimproved (n = 40) groups on the basis of preestablished criteria following 6 months of treatment. Patients were administered the structured interview for DCPR at baseline and the Gastrointestinal Symptom Rating Scale both at baseline and follow-up. Results: In the unimproved patients, the prevalence of the DCPR categories of alexithymia (82.2%) and persistent somatization (72.5%) was significantly higher while health anxiety was more prevalent in improved patients (21.5%). No unimproved patient lacked a DCPR diagnosis while multiple DCPR diagnoses were significantly higher in the unimproved group (90%). In the regression analysis, alexithymia, persistent somatization, a higher number of DCPR diagnoses for each patient and, to a lesser extent, greater symptom severity at baseline were significant predictors of unimprovement. Health anxiety, even after controlling for gastrointestinal symptoms, was a significant predictor of improvement. Conclusion: The ability to predict treatment outcome indicates the clinical utility of the DCPR. Clinicians may improve treatment outcome for FGID patients by identifying particular psychosomatic syndromes (alexithymia, persistent somatization, and health anxiety) and patients with multiple DCPR clusters, and attempting to address specific therapeutic interventions.