The Irritable Bowel Syndrome and Psychiatric Disorders in the Community: Is There a Link? Nicholas J. Talley, M.D., Ph.D., F.R.A.C.P., F.A.C.G., Stuart Howell, B.A. (Hons), and Richie Poulton, Ph.D. Department of Medicine, University of Sydney, Nepean Hospital, Penrith, Australia OBJECTIVE: Psychiatric morbidity is high among patients who present to referral centers with irritable bowel syn- drome (IBS). However, few studies have investigated the relationship between psychiatric disturbance and IBS in community samples. We hypothesized that psychiatric dis- orders are linked to IBS in the general community, but this is influenced by the criteria used to establish a diagnosis of IBS. METHODS: The data were collected from a birth cohort born in Dunedin (New Zealand) between April 1972 and March 1973. This cohort consisted of 1037 members (52% male), who were assessed at ages 3, 5, 7, 9, 11, 13, 15, 18, 21, and 26 yr. GI symptoms were recorded at age 26 yr, using an abbreviated version of the Bowel Symptom Questionnaire; psychiatric history was obtained at ages 18 and 21 yr, using a modified version of the Diagnostic Interview Schedule. RESULTS: The prevalence of IBS was 12.7% according to the Manning criteria and 4.3% according to the Rome II criteria. The IBS was not significantly related to a diagnostic history for psychiatric illness overall, nor to a history of anxiety disorders, depressive disorders, and substance de- pendence. These results were independent of the IBS criteria used; there was no association between psychiatric history and IBS when IBS was defined according to the Manning criteria (p = 0.11 to 0.98) or the Rome criteria (p = 0.18 to 0.92); Rome and Manning criteria subjects did not signifi- cantly differ from each other in terms of psychiatric history (p = 0.16 to 0.89). CONCLUSION: In a cohort of young adults with IBS from New Zealand, IBS appears to not be related to psychiatric disorders. (Am J Gastroenterol 2001;96:1072–1079. © 2001 by Am. Coll. of Gastroenterology) INTRODUCTION The irritable bowel syndrome (IBS) is a common yet still poorly understood disorder (1–3). In studies from referral centers, the frequency of depression, anxiety, and other major Diagnostic and Statistical Manual (DSM) Axis 1 psychiatric disorders is high in patients with IBS (1). Indeed, up to 60% with IBS have been reported to have a psychiatric disorder, which was considerably higher than the rate of psychiatric disorders in organic disease or healthy controls (4 –10), suggesting a causal association. However, it is largely unknown whether this rate of psychiatric disorders is as high in the community, or whether psychiatric disorders apply exclusively to those subjects who have sought health care. This issue can only be addressed in adequate popula- tion-based studies. Studies from volunteers in the United States have re- ported that psychological disturbances were higher in IBS patients than in those who had the symptoms but who had not sought medical care (IBS nonpatients) (11, 12). How- ever, these studies did not evaluate psychiatric diagnoses. We postulated that psychiatric disorders would be highly prevalent in subjects from the community who meet diag- nostic criteria for the IBS compared to controls. Following the recognition by Manning et al. that symp- toms could positively identify patients with IBS (13, 14), the Manning criteria have been applied in epidemiological stud- ies to determine the prevalence of IBS; approximately 10 – 15% of the population report IBS symptoms using these criteria (15). Subsequently, the more restrictive Rome cri- teria have been applied for diagnosis; the prevalence of IBS is 4 –9% applying these new criteria (16). Whether those subjects who only fulfill the Manning but not Rome criteria truly have IBS is unclear. Moreover, whether applying more rigorous symptom criteria identifies those with higher or lower rates of psychiatric disturbance is unknown. We hy- pothesized that those subjects who fulfill the Rome II cri- teria for IBS would have less psychiatric disturbance than those fulfilling the Manning criteria but not the Rome cri- teria. We speculated that subjects fulfilling the Manning criteria alone would be those with a somatic disorder rather than a true functional disorder of the GI tract. We tested these hypotheses in a birth cohort that has very carefully categorized subjects in the first 26 yr of life in terms of both psychiatric diagnoses and GI tract symptoms. MATERIALS AND METHODS Sample Participants were members of the Dunedin Multidisci- plinary Health and Development Study. This is a longitu- dinal investigation of the health, development, and behavior of a complete cohort born between April 1, 1972, and March THE AMERICAN JOURNAL OF GASTROENTEROLOGY Vol. 96, No. 4, 2001 © 2001 by Am. Coll. of Gastroenterology ISSN 0002-9270/01/$20.00 Published by Elsevier Science Inc. PII S0002-9270(01)02304-8