Core mental state in irritable bowel syndrome

Psychiatric illness is higher among patients with irritable bowel syndrome (IBS) who seek medical care; however, a specific psychopathology that differentiates patients with IBS from patients with other organic gastrointestinal disorders has not been found. In the study described here, we investigated the predominant psychiatric symptoms in women with IBS.

The criteria of Manning et al., as modified by Thompson et al., were used to make the diagnoses of IBS. Psychiatric assessment was performed by using a structured interview in 64 women, aged 20 to 70 years, 36 with IBS and 28 with chronic cholelithiasis. Diagnosis of chronic cholelithiasis was made by histopathological examination. The final diagnoses were confirmed by interview after 1 year. The diagnostic system based on the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) was used to make the current diagnoses. The Present State Examination (PSE)-Index of Definition (ID) computer program (CATEGO) was used to define total psychopathology (total PSE score), current clinical severity (ID), and clusters of psychiatric symptoms.

No difference in the specific DSM-IV diagnostic categories was found, but there were more total depressive disorders in the IBS group. The ID and total PSE score were high among patients with IBS. Multiple logistic regression analysis showed that duration of gastrointestinal pain, and the symptoms of general anxiety, and hypochondriasis significantly predicted a diagnosis of IBS.

Female patients with IBS are categorized into the general DSM-IV category of depressive disorder, their current psychiatric severity is high compared with that of women with chronic cholelithiasis, and patients with IBS are characterized by the psychiatric syndromes of general anxiety and hypochondriasis. The implications of these findings and areas for future research are discussed.