Gastrointestinal-specific Anxiety in IBD: Associations with Disease Activity, Psychological Symptoms, and Serotonergic Polymorphisms

Objective: Many people living with an inflammatory bowel disease (IBD) experience persistent abdominal symptoms even in the absence of active inflammation. These symptoms are referred to as irritable bowel syndrome (IBS)–like symptoms. Gastrointestinal-specific anxiety (GSA) is a common feature of disorders of gut-brain interaction and may also be relevant in patients with IBD experiencing IBS–like symptoms. Methods: This cross-sectional study examined the associations between psychological variables and GSA in individuals with IBD in different states of disease activity (n=308, age: 42.4±19.4; female: 183, male: 125). In two subsamples of 83 patients (age: 41.2±15.9; female: 37, male: 46) and 70 patients (age: 42.1±16.1; female: 32, male: 38), links to single-nucleotide polymorphisms (SNPs) in genes related to serotonin signaling and serum tryptophan metabolites, respectively, were explored. Results: Psychological variables including anxiety (β=.393, P <.001) and depression (β=.284, P <.001) predicted GSA levels. Genetic analyses revealed associations for serotonergic variants; however, none of these associations remained statistically significant after correction for multiple testing. While disease activity was linked to GSA (β=.171, P =.002), inflammatory biomarkers and tryptophan metabolites did not exhibit any significant associations. Conclusions: Our findings suggest that GSA as a specific type of anxiety is strongly related to psychological symptoms in IBD. Anxiety was the strongest predictor of GSA, contributing even more strongly to GSA than disease activity. Screening patients for GSA could help to detect disturbances in gut-brain-interactions and improve individualized treatment.