Prospective analysis of association of depression with risk of colorectal cancer and polyps in the Nurses’ Health Study II

Depression has been linked to chronic diseases, including cancer. Chronic stress may promote colorectal carcinogenesis via hormonal, immune, and metabolic abnormalities. Analysis among participants of the prospective Nurses’ Health Study II (1993-2019) investigated the association of depression with colorectal cancer risk (among 91,383 women) and risk of adenoma and serrated polyps (among 62,237 women). Depression was defined as a Mental Health Index-5 score ≤ 52, antidepressant use, or physician-diagnosed depression. Over 2.36 million person-years of follow-up, 474 colorectal cancer cases were documented. Depression was modestly associated with lower risk of colorectal cancer (HR 0.76; 95% CI 0.59-0.97) and colon cancer but not rectal cancer. Among 62,237 women undergoing lower endoscopy over 24 years, 4,104 conventional adenomas and 4,563 serrated polyps were documented. Depression was modestly inversely associated with overall and large conventional adenomas (OR 0.76; 95% CI 0.63-0.92). No consistent association was observed with serrated polyps. The authors conclude that depression was inversely associated with colorectal cancer and large conventional adenomas.