Background and Aims:The present study aimed to find psychiatric morbidity, stress, anxiety, and depression in patients with irritable bowel syndrome (IBS) and compare it with patients having non-ulcer dyspepsia (NUD).Methods:This case NUD study compared 50 patients each with IBS and NUD. The two groups were compared on demographic data, psychiatric diagnosis using the Structured Clinical Interview for DSM-IV Axis 1 disorders, anxiety levels using the Hamilton Anxiety Rating Scale (HAM-A), and depression using the Hamilton Depression Rating Scale (HAM-D). The Presumptive Stressful Life Events Scale (PSLES) was used to measure stress.Results:The cases of IBS were more likely to be of female gender (P = 0.012), married (P = 0.009), and employed (P < 0.001). Psychiatric diagnoses were more common in the cases of IBS than NUDs (88% vs. 30%, P < 0.001), the most common being major depression and somatization disorder. Symptoms of anxiety and depression were more common in patients with IBS (P < 0.001 for HAM-A and HAM-D). Logistic regression revealed that having IBS and increased age were independent predictors of having a psychiatric diagnosis.Conclusions:IBS is associated with the considerable degree of psychiatric morbidity. Adequate attention should be paid toward comorbid psychiatric illnesses, and prompt treatment should be instituted.