Factors associated with depression in people with inflammatory bowel disease: The relationship between active disease and biases in neurocognitive processing

Background: Depression is common among people with inflammatory bowel disease (IBD), though the causes remain unclear. We conducted a cross-sectional study to investigate the role of emotional processing biases in contributing to depression among people with IBD.

Materials and methods: One hundred and twenty outpatients with IBD were recruited and: (a) completed questionnaires to record: age, sex, social support, socioeconomic status, anxiety and depression (n = 104), (b) underwent assessments of biases in emotional recognition (n = 112), emotional memory and reinforcement learning (c) had recorded from clinical records: type of IBD, duration of IBD, IBD activity and (d) provided blood for high-sensitivity C-reactive protein levels (n = 99).

Key results: Sixty-eight participants had Crohn's disease and 49 had ulcerative colitis. Of these, 35 had active disease and 26 had depression. Those with depression were more likely to be female, lack social support, have active disease, be taking corticosteroids but not TNF-alpha inhibitors and exhibit less positive emotional recognition bias. On multivariable regression analysis, depression was associated independently with lack of social support (unstandardized regression coefficient (B) = -1.40, P = 0.02) and increased disease activity (B = 1.29, P = 0.03). Causal steps analysis was consistent with less positive emotional recognition bias partially mediating the effects of disease activity on depression.

Conclusions and inferences: This is the first study to demonstrate links between disease activity and less positive biases in emotional recognition that could explain higher rates of depression among people with active IBD. Future prospective studies are required to confirm the effects of emotional processing biases in depression and allow stronger causal inferences to be drawn.