Patients with depression are more than twice as likely to be diagnosed with inflammatory bowel disease compared with those without depression, according to a systematic review.

The inverse relationship was also confirmed, Danish researchers said, with ulcerative colitis and Crohn’s disease being linked to a near 50% elevated risk of depression and anxiety.

This bidirectional association was clinically relevant and pointed to “shared or mutually dependent disease mechanisms”, they concluded in General Hospital Psychiatry.

Their review included seven studies on the incidence of anxiety and depression in 152,000 patients with inflammatory bowel disease (IBD) and two studies on the risk of IBD among 420,000 individuals with either mental health diagnosis.