*5.5.1 The bidirectionality in IBD*

According to a study that assessed perceptions of stress over time (2 years) in three subgroups, those with chronically active symptoms had the greatest perceptions of stress over time [261]. Over time, those with chronically inactive symptoms displayed the lowest levels of perceived stress [261]. Perceived stress scores were intermediate between those whose symptoms fluctuated from inactive to active over the 2-year period. In these studies, the directionality of the association between adverse mental health and active symptoms of disease could not be established [262]. They do indicate, however, that adverse mental health is a problem for those whose disease is symptomatic. Psychological comorbidity is three times more prevalent in people with IBD than in the general population [262, 263]. More than 25% of patients with IBD may suffer from depression and more than 30% from anxiety during their lifetime [262, 264, 265]. Study of the Manitoba IBD Cohort Study population that underwent the CIDI and comparison with the Canadian Community Health Survey population that did the CIDI revealed that people with IBD were twice as likely to have a lifetime history of mood disorders than controls both within 12 months of diagnosis and within a year following diagnosis [262, 264]. Nearly 80% of those with IBD and an anxiety disorder had their anxiety disorder diagnosed more than two years before their IBD diagnosis. It is estimated that more than 50% of those with mood disorders were diagnosed before they were diagnosed with IBD. Therefore, it seems that not just chronic disease symptoms can lead to an increased level of anxiety and depression, but the presence of these psychological diseases could also predispose a person to develop IBD [262].
