Symptoms of depression may increase risk for gastrointestinal symptoms and subsequently predate the development of Inflammatory Bowel Disease (IBD) by up to 9 years. These findings are based on the results of a study published in Gastroenterology.
This large, nested case-control study included 13,681 incident cases of Ulcerative Colitis (UC) and 5874 incident cases of Crohn disease (CD) between January 1998 and May 2016. Cases were pulled from the Clinical Practice Research Datalink (CPRD) database in the United Kingdom and then compared with 54,724 and 23,496 age and sex matched controls.
The researchers found that in cases with data spanning at least 5 years (UC=10,829, CD=4531), patients with depression had an increased risk of developing UC (Odds Ratio [OR] 1.25; 95% Confidence Interval [CI], 1.03-1.52), but not CD (OR 1.21; 95% CI, 0.90-1.63). In this same analysis, after adjusting for smoking and socioeconomic status, no significant association between depression and incidences of UC or CD were identified, unless there was a history of prior gastrointestinal symptom-reporting in those with a new diagnosis of UC (OR 1.52; 95% CI, 1.19-1.94) but not CD (OR 1.21; 95% CI, 0.82-1.77).
When researchers broadened the definition of depression, it became associated with incident IBD diagnosis, but this was only significant in those with previous gastrointestinal symptoms (OR 1.47; 95% CI, 1.21-1.79 and OR 1.41; 95% CI, 1.04-1.92 for incident diagnoses of UC and CD, respectively).
The study authors reported there was “an increase in the prevalence of depression in the years predating a diagnosis of IBD, noting a divergence in trend from the general population, up to 9 years prior to diagnosis”. They added, “This tendency would support the theory that a chronic depressive disorder is a risk factor for the manifestation of gastrointestinal symptoms and linked to a later diagnosis of IBD.”
Limitations of this study include the nested case-control design which may have led to error and selection bias. Additionally, patients who pursued psychotherapy treatment were excluded from study inclusion criteria. Lastly, there may have been overlap with other psychological comorbidities or even functional gastrointestinal disorders.
Nevertheless, the researchers determined that the combination of depression and gastrointestinal symptoms may increase the risk for the development of IBD, and that this risk may exist up to approximately 10 years before diagnosis. These findings highlight the importance of proactively treating these comorbid conditions.
Fairbrass KM, Gracie DJ, Ford AC. Healthy mind, healthy body: chronic depression may pre-date the development of IBD by up to 9 years. Gastroenterology. Published online February 4, 2021. doi: 10.1053/j.gastro.2021.02.004.