A review of studies of psychiatric factors in Crohn's disease: etiologic implications.
Researchers have recently challenged long-held concepts of psychological origins to inflammatory bowel disease, in particular with ulcerative colitis. The purpose of this paper is to review published studies on psychiatric factors in Crohn's disease to determine whether available evidence points to the absence or presence of a significant relationship between Crohn's disease and stressful life events or psychiatric symptoms or disorders. Twelve articles with > or = 10 subjects on which statistical data were reported from standardized instruments of measure were found. Most reported a significant association between Crohn's disease and psychiatric factors. Many of the investigative groups reporting such an association in Crohn's disease had also studied ulcerative colitis and failed to find a similar association in that disease. Published data indicate that Crohn's disease, unlike ulcerative colitis, may be statistically associated with lifetime psychiatric disorders. This association appears to be more modest than in irritable bowel syndrome, in which far higher rates of psychiatric disorders are reported than in Crohn's disease.