DCPR-R and Somatic Symptom Disorder in Patients with Severe Irritable Bowel Syndrome

Background: Doubts have been expressed in literature whether the new revised DSM-5 category of Somatic Symptom Disorder (SSD) may meet the basic requirements of clinical utility in the identification of the psychological factors influencing the course of medical disorders. The aim was to investigate the ability of SSD and DCPR-R criteria to identify patients with more severe manifestations of Irritable Bowel Syndrome (IBS) symptoms who are often seen by clinicians as difficult patients. To our knowledge this is the first study investigating SSD and DCPR-R in severe IBS and therefore no a priori expectation could be stated. Methods: Consecutive 203 IBS patients were recruited. They were evaluated for SSD by the combined use of PHQ-15 and WI-7, DCPR-R syndromes with the related semi-structured interview, severity of IBS with the IBS-SSS scale, psychological distress with the HADS, and psychosocial functioning with the SF-12. Results: Twenty-seven percent of patients fulfilled criteria for SSD, 90% for at least one DCPR-R (mainly alexithymia, persistent somatization, demoralization, and allostatic load), and 20% for both DCPR-R and SSD. The presence of DCPR-R alexithymia and persistent somatization were associated with IBS severity with large effect size (d=1.18) that was even more than with the joint presence of SSD (d=1.07). Conclusions: Betweengroup comparison and multivariate regression showed DCPRR alexithymia and persistent somatization, but not SSD, predicted more severe forms of IBS, after controlling for psychological distress and psychosocial functioning.