Psychological disorders in gastrointestinal disease: epiphenomenon, cause or consequence?

BACKGROUND Psychological disorders have been associated with irritable bowel syndrome (IBS) for decades in the absence of other objective etiology. However, such associations are also evident in other chronic diseases with more clearly defined pathogenesis such as ulcerative colitis. In this study, we examined the prevalence and severity of psychological disorders among IBS and ulcerative colitis (UC) patients relative to healthy controls. METHODS A review was conducted of English-language literature to identify case-control studies reporting the prevalence of depression or anxiety in IBS and UC populations relative to healthy controls. Our primary endpoint was the pooled prevalence or average score of depression or anxiety in an IBS or UC population relative to healthy control. RESULTS Seven case-control studies evaluating IBS and three evaluating UC were included. All IBS and UC studies reported excess prevalence and severity of depression as well as anxiety, relative to healthy controls. The prevalence of depression in excess of healthy controls was 39% in UC case-control trials and 33% in IBS studies, and excess anxiety was present in UC (42%) and IBS (19%) case-control trials as well. Anxiety and depression scores were higher (representing more severe symptoms) in both UC and IBS patients compared to healthy controls. CONCLUSIONS Anxiety and depressive disorders are associated with both IBS and UC. The non-specific association between these psychological and gastrointestinal disorders could suggest that chronic gastrointestinal illness might affect psychosocial behavior.