New-onset depression after colorectal cancer diagnosis: a population-based longitudinal study

To date, no large studies examining the temporal relationship between colorectal cancer (CRC) and the subsequent development of depressive disorders exist. We aimed to assess the incidence of depression post-colorectal cancer (CRC) diagnosis. To conduct this longitudinal study, we searched the large US population-based database, Explorys (IBM), from January 1, 1999, to January 1, 2021. We investigated new-onset depression and its associated mortality as well as the role of the mental health provider post-CRC diagnosis. Confidence intervals were calculated for all outcomes and multivariate regression analysis was performed. Incident depression post-CRC diagnosis was 20.8 vs 8.9 per 100 person-years [OR 3.46, p   65 years (OR: 5.17). Referral to a mental health provider resulted in significantly lower all-cause mortality (3.6% vs 26.9%; p < 0.0001). Our findings advocate for initiating depression screening for high-risk patients post-CRC diagnosis and prompt mental health provider referral.