Timing of mental disorders in relation to cancer-specific mortality in cancer patients

To evaluate whether mental disorders identified before cancer diagnosis, within one year, or 2-5 years after cancer diagnosis are associated with cancer-specific mortality, and whether having both pre- and post-diagnosis disorders displays the highest mortality.

We conducted a cohort study of 22,281 UK Biobank participants linked to cancer and death registries. Mental disorders were ascertained from inpatient and outpatient diagnoses and psychiatric prescriptions, then categorized by period. We applied period-specific longitudinal inverse probability weighting to preserve early-period information and estimate time-specific effects, with treatment and death censoring weights to reduce confounding and survival bias. Weighted Cox models estimated hazard ratios (HRs) and 95% confidence intervals (CIs) overall and by site (prostate, breast, colorectal, lung, and lymphoma). Additional models evaluated pre-only, post-only, and both pre- and post-diagnosis disorders versus none.

Over median 5.3 year follow-up, 6,134 cancer-specific deaths occurred. Mental disorders were associated with higher overall cancer mortality: pre-diagnosis (HR [95% CI]: 1.19 [1.11,1.27]), first year post-diagnosis (1.38 [1.26,1.51]), and years 2-5 (2.19 [1.97,2.43]). Associations were strongest and most consistent during years 2-5 across sites (HRs, 1.58-2.27). Site-specific analyses additionally showed elevated hazards for pre-diagnosis and first-year disorders in lymphoma and first-year disorders in colorectal cancer. Patients with post-diagnosis mental disorders, regardless of pre-diagnosis status, had higher cancer mortality than those with pre-diagnosis disorders only or none.

Mental disorders were associated with cancer-specific mortality throughout the continuum, with the strongest associations in years 2-5 across multiple sites. Findings support routine mental-health screening and intervention in survivorship care.