Irritable bowel syndrome (IBS) is a gut–brain axis disorder which is characterized by recurrent abdominal pain and changes in bowel habits.1 The global prevalence of IBS is estimated to be around 4–11%; however, variations exist in the incidence of the disease among countries and regions.2, 3 As a chronic disorder with relapsing symptoms over time, quality of life of patients is often severely affected. In addition, IBS represents a substantial economic burden for the healthcare system with predicted direct costs up to $7.000 per patient per year.4

Although the etiology of IBS is not fully understood, there is evidence indicating that an alteration of the gut–brain axis is involved in its pathophysiology.5 Visceral hypersensitivity, low-grade chronic inflammatory responses in the intestinal mucosa, intestinal microbiota changes, and psychological stress are considered possible factors leading to abnormal gut–brain interactions in these patients.6, 7, 8 For this reason, IBS has been linked with several comorbid psychological and mental disorders such as anxiety or depression.9, 10, 11

Depression is one of the most prevalent psychiatric conditions and is included as one of the top contributors to global disability.12 Previous research has shown that patients with IBS are significantly more likely to experience depression, as compared to healthy individuals.13 The understanding of the connection between these two highly prevalent and concurrent disorders remains critical for potential new therapeutic approaches.

The aim of this study was to determine the prevalence of intestinal and extra-intestinal symptoms according to depression severity in a large cohort of patients with IBS.