Association between depressive symptoms and incidence of Crohn's disease and ulcerative colitis: results from the Nurses' Health Study

Depression and psychosocial stress are believed to contribute to the pathogenesis of Crohn's disease (CD) and ulcerative colitis (UC). Although many mechanisms have been proposed to link these disorders, few prospective studies have examined the relationship between depressed mood and incidence of CD or UC.

We analyzed data from 152,461 women (aged 29-72 years) enrolled since 1992-1993 in the Nurses' Health Study cohorts I and II. Self-reported depressive symptoms were assessed by using the Mental Health Index (MHI)-5, a validated 5-item subscale of the 36-item Short-Form health survey, which is designed to estimate psychological distress on the basis of scores that range from 0 to 100. Self-reported CD and UC were confirmed through blinded record review by 2 gastroenterologists. Cox proportional hazards models were used to associate recent (within 4 years) and baseline MHI-5 scores with risk for CD or UC, adjusting for other risk factors.

During 1,787,070 person-years of follow-up, we documented 170 cases of CD and 203 cases of UC. Compared with women with recent MHI-5 scores of 86-100, women with recent depressive symptoms (MHI-5 scores <52) had an increased risk of CD (multivariate-adjusted hazard ratio [HR], 2.39; 95% confidence interval [CI], 1.40-3.98; P trend = .001). Baseline depressive symptoms, assessed from the baseline MHI-5 score, were also associated with CD, although with a lower HR (1.62; 95% CI, 0.94-2.77). Recent (HR, 1.14; 95% CI, 0.68-1.92) and baseline depressive symptoms were not associated with increased risk of UC (HR, 1.07; 95% CI, 0.63-1.83).

On the basis of data from the Nurses' Health Study, depressive symptoms increase the risk for CD, but not UC, among women. Psychological factors might therefore contribute to development of CD. Further studies are needed to determine the mechanisms of this association.