Mediating Role of Negative Affectivity in the Association Between Lifetime Trauma and Gastrointestinal Symptoms

Background/Objectives: It is increasingly recognized that traumatic life experiences render individuals more vulnerable to gastrointestinal (GI) symptoms and chronic bowel conditions like inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS). In this study, we examined whether this effect is mediated by negative affectivity. Methods: A total of 281 participants recruited in the Netherlands, including 94 with IBD, 95 with IBS and 92 controls, were assessed for lifetime trauma, trait anxiety, depression, and GI (IBD/IBS) disease activity. Results: The results confirmed that negative affectivity fully mediated the association between trauma and GI symptomatology, with trauma and depression explaining 38-40% (IBD|IBS) of the variance in disease activity and trauma and anxiety explaining 31-33% (IBD|IBS) of the variance in disease activity. Upon correction for condition (patient/controls), the predictive capacity increased even further, with trauma and depression now accounting for 43-44% (IBD|IBS) and trauma and anxiety for 40% (IBD and IBS) of the GI symptom heterogeneity. Conclusions: The results are in line with studies linking trauma to negative affectivity and negative affectivity to a more aggressive GI disease course. More generally, they show that the somatic and affective consequences of trauma should not be considered in isolation but must be treated as a covariant whole.