Injurious falls before, during, and after depression diagnosis: Results from two longitudinal population-based studies

BACKGROUND: To investigate the association between injurious falls and depression and examine the long-term trajectory of injurious falls before, during, and after depression diagnosis. METHODS: This population-based study analyzed data obtained from two prospective cohorts: the UK Biobank (n = 435,662; 2006-2023) and the Swedish Twin Registry (STR; n = 43,740; 1998-2016). Injurious fall trajectories were assessed using 16,918 matched pairs from the UK Biobank and 2004 pairs from the STR, where each individual with depression was matched to a depression-free counterpart by birth year and sex. Annual injurious falls and incident depression were observed during follow-up. RESULTS: Multi-adjusted models showed that experiencing an injurious fall at any age was associated with an increased risk of depression in both UK Biobank (hazard ratio [HR] = 1.44, 95% confidence interval [CI] = 1.31-1.58) and STR (odds ratio [OR] = 1.48, 95% CI = 1.09-2.02). This association was particularly strong for individuals who fell before age 45 (UK Biobank: HR 1.53 [1.27-1.83]; STR: OR 3.51 [1.95-6.30]) and after age 60 (UK Biobank: HR 1.48 [1.22-1.80]; STR: OR 1.81 [1.03-3.18]). In the STR, injurious fall incidence began rising 3 years pre-diagnosis (IRR 1.63 [1.15-2.31]) and gradually declined 6 years post-diagnosis (incidence rate ratio [IRR] = 1.58, 95% CI = [1.11-2.26]). CONCLUSIONS: Injurious falls, especially those occurring before age 45 or after age 60, are associated with a higher risk of subsequent depression. The trajectory of injurious falls among individuals with depression begins increasing three years before diagnosis and peaks in the year of diagnosis.