[Psychiatric comorbidities in patients referred for irritable bowel syndrome]

To assess the prevalence of psychiatric comorbidities in patients referred for irritable bowel syndrome (IBS) with questionnaires for mental disorders.

A total of 83 IBS patients at our hospital were enrolled and assessed with the Personality Diagnostic Questionnaire for DSM-IV, version 4 (PDQ-4) and Composite International Diagnostic Interview, version 3.0 and 2.1 (CIDI-3.0 & CIDI-2.1) by trained interviewers. Such items as personality dysfunction, mental disorder and somatization disorder were examined.

The male-female ratio was 1.08/1. Their mean age was (38 ± 14) years old. Among them, 20 patients (24.1%) were constipation-predominant, 31 (37.3%) diarrhea-predominant, 15 (18.1%) mixed and 17 (20.5%) unclassified type. (1) Sixty-two (74.7%) patients scored positive for any personality dysfunction. There was no significant gender difference. The cluster C (anxious-fearful) personality disorder was most commonly found in IBS patients (n = 58, 69.9%). The prevalence of somatoform disorders plus personality dysfunction was 46.8% (29/62). It was significantly higher than those without personality dysfunction [19.0% (4/21), P = 0.025]. (2) Thirty-seven patients (44.6%) had a lifetime CIDI-3.0 diagnosis. It was significantly higher than that in the general population. There was no gender difference. Anxiety and mood disorders were the most common types of psychiatric comorbidities [n = 21 (25.3%) and n = 19 (22.9%) respectively]. The lifetime prevalence of alcohol or nicotine abuse and(or) dependence and intermittent explosive disorder were 10.8% (n = 9) and 8.4% (n = 7). Psychiatric comorbidities were most commonly found in diarrhea-predominant patients (58.1%). But there was no significant difference among the subgroups. (3) Thirty-three patients (39.8%) had somatoform disorders. Neither gender nor subgroup difference was observed. The IBS patients with anxiety disorders presented significantly more somatoform disorders than the remainders [61.9% (13/21) vs 32.3% (20/62), P = 0.016].

Such psychiatric comorbidities as anxiety disorders and mood disorders are common in patients referred for IBS. The patients with personality dysfunction and(or) anxiety were more likely to suffer somatoform disorders. A gastroenterologist should grasp a thorough knowledge and make appropriate therapeutic recommendations for those patients.