Are Inflammatory Bowel Disease and Depression Interrelated?

New study shows bidirectional link between inflammatory bowel disease and depression and the link also extends to siblings of patients with IBD or depression.

Inflammatory bowel disease (IBD) is a chronic condition involving inflammation of the digestive tract that affects approximately 1.6 million Americans. Depression affects more than 16 million Americans.

A new study from Keck Medicine of //University of Southern California shows that patients diagnosed with IBD are nine times more likely to develop depression than the general population. In addition, their siblings who are not affected by IBD are almost twice as likely to develop depression.

In contrast, patients with depression are twice as likely to develop IBD and their non-depressed siblings are one and a half times more likely to develop IBD.

“This research reveals a clinical overlap between both conditions, and is the first study to investigate the two-way association between IBD and depression in siblings,” said Bing Zhang, MD, a gastroenterologist with Keck Medicine and co-lead author of the study. This research has been explained in detail in the Journal of Gastroenterology and Hepatology.

Data of Taiwanese Residents Regarding IBD and Depression

Zhang and his fellow researchers analyzed data from more than 20 million people from Taiwan’s National Health Insurance Research Database, which contains detailed medical information about more than 99% of Taiwanese residents.

For 11 years, they tracked patients with inflammatory bowel disease (IBD) or depression and their siblings without either condition, comparing the onset of depression or IBD with a control group without either condition, but of the same age, gender and socioeconomic status.

Inflammatory Bowel Disease - Causes, Symptoms, Diagnosis, Treatment & Prevention
Inflammatory bowel disease involves chronic inflammation of the colon and small intestine. Symptoms include diarrhea, abdominal pain and weight loss.

Zhang hypothesizes that many factors may contribute to the bidirectional nature of disorders, including environmental stresses, intestinal microbes (including bacteria, fungi and viruses) and genetics.

“The finding that people with IBD are more prone to depression makes sense because IBD causes constant gastrointestinal symptoms that can be very disruptive to a patient’s life,” he said. “And the elevated depression risk among siblings of IBD patients may reflect caregiver fatigue if the siblings have a role in caring for the patient.”

What has surprised the researchers is that patients with depression are more likely to develop IBD. Zhang speculates that this finding may be related to a scientifically established connection known as the gut–brain axis, which contains the spinal cord and the brain.

For example, he said that inflammation of the brain that plays a role in depression may be linked to inflammation of the gastrointestinal tract, which is a hallmark of IBD.

Researchers do not know why siblings of patients with depression are more likely to be diagnosed with IBD. Zhang speculates that family members may be genetically predisposed to the disease, which may appear different.

Zhang hopes that the results of this study will motivate health professionals to consider family history and the relationship between gastrointestinal and mental disorders when evaluating or treating patients with IBD or depression.

Through further research and better understanding of the gut–brain axis, he considers improving the new link between conditions to improve the prevention, diagnosis and treatment of IBD and mental disorders.

Source-Medindia