10/23/2026
Depression and gastrointestinal disorders frequently occur together. University of California, Irvine experts wondered if knowing which tends to be diagnosed first could shed light on the well-established but not yet fully understood gut-brain connection.
Researchers analyzing large-scale electronic health records found a striking difference among three common conditions. Depression was typically diagnosed before irritable bowel syndrome. With Crohn’s disease, the pattern was reversed, with the gastrointestinal disorder more often diagnosed first. Ulcerative colitis fell somewhere in between.
“IBS and Crohn’s disease are fundamentally different diseases,” says the study’s corresponding author, Gha-Hyun Jeffrey Kim, Pharm.D., Ph.D., assistant professor of clinical pharmacy practice at the UC Irvine School of Pharmacy & Pharmaceutical SciencesSciences and a member of the Robert A. Mah Molecular Innovation Center. “IBS involves changes in how the brain and gut communicate, including how gut signals are processed. That means problems on the brain side, like depression, can show up first and then shape what happens in the gut.”
Read more about the study at this link: https://news.uci.edu/2026/10/14/untangling-the-link-between-depression-and-gut-disease/
Image Description: Study’s corresponding author, Gha-Hyun Jeffrey Kim inspects a petrie dish alongside another person in a lab coat. Photo by Steve Zylius.