That Gut Feeling: The Role of Inflammatory Cytokines in Depression Among Patients with Inflammatory Bowel Disease

There is mounting evidence of an associative link between inflammatory bowel disease (IBD) and clinical depression. In the first major treatise on the eponymous disease, Burrill Crohn himself noted that: “The number of cases of ileitis that have been rescued from institutions for the treatment of mental diseases emphasises not the personality but the end results of the drain of the disease upon the psychic constitution of the sufferer.” In the 70 years since that prescient statement, a high incidence of neuropsychiatric symptoms (depression, anxiety, cognitive fatigue, and sleep disorders) in patients with IBD has been frequently observed. Since patients with depression have significantly increased rates of relapse, surgery, hospitalisation, and suicide, recognising and treating depression is of paramount importance. In this narrative review, the authors will trace some of the biochemical connections between intestinal inflammation and neuropsychiatric symptoms and focus on strategies to manage both. Additionally, the authors offer a cautionary reflection on the extant need for widespread screening for depression among patients with IBD.