Beyond the diagnosis: Mental health trends among patients with cancer—A retrospective cohort study.

329 Background: There remains limited research on the prevalence of mental health disorders (MHD) among patients with different cancer types in representative populations. This study explores the prevalence of MHD before, during, and after a diagnosis of cancer across a broad community population. Methods: This retrospective study examined MHD (including depression, anxiety, PTSD and substance use) among adults diagnosed with cancer from January 1, 2018, to December 31, 2022, within Kaiser Permanente Northern California. Monthly trends of MHD prevalence from pre-diagnosis to one-year post-diagnosis of cancer were stratified by cancer type, evaluated using linear regression, and compared to healthcare utilization. Results: The study cohort comprised 58,591 patients (median age 65, 51.5% female, 57.9% white). Across all cancer types, prevalence of total pre-existing MHD was 18.9% (95% CI 18.6, 19.3), which increased to 23.7% (95% CI 23.3, 24.0) at cancer diagnosis, and up to 33% (95% CI 32.6, 33.5) by one-year following diagnosis. Anxiety was the most common, more than doubling from a pre-cancer prevalence of 11.6% (95% CI 11.4, 11.9) to 24.6% (95% CI 24.2, 25.0) one year after diagnosis. Depression prevalence also increased over the same period, from 11.5% (95% CI 11.3, 11.8) to 18.3% (95% CI 18.0, 18.7). While less common overall, substance use also more than doubled over the one-year period, from 1.9% (95% CI 1.8, 2.0) to 4.7% (95% CI 4.5, 4.9). The lowest prevalence for all MHD was seen in prostate cancer, at 13.4% pre-diagnosis to 21.7% one-year post-diagnosis. The highest rates of total MHD were seen amongst brain cancer and acute leukemia, at 23.0% (brain) and 19.2% (leukemia) prior to cancer, to 50.1% (brain) and 48.1% (leukemia) one year after. Mental health care also increased modestly during this one-year period from pre- to post-cancer diagnosis. Utilization of Psychiatric services across all cancers increased from 5.8% (95% CI 5.6, 6.0) to 10.9% (95% CI 10.6, 11.2). Use of Behavioral Health services was low overall, noting a shift from 1.7% (95% CI 1.6, 1.8) to 4.2% (95% CI 4.1, 4.4). Conclusions: There is a growing burden of MHD in patients with cancer, with variations by cancer type and increases in prevalence just after cancer diagnosis. Use of mental health services amongst this population remains low. Studies characterizing MHD across different cancer populations can help prioritize screening and timely interventions, improving the mental health burden and overall outcomes in cancer care. Prevalence of mental health disorders (MHD); % (n). Month(0 = at cancer diagnosis) -1 (n=58591) 0 (n=58591) 12 (n=47931) p-value Depression 11.5% (6764) 13.5% (7912) 18.3% (8774) <0.0001 Anxiety 11.6% (6822) 15.4% (9015) 24.6% (11790) <0.0001 Substance Use 1.9% (1125) 2.9% (1693) 4.7% (2233) <0.0001 All MHD* 18.9% (11097) 23.7% (13858) 33.0% (15840) <0.0001 *Includes depression, anxiety, PTSD, and substance use.