Background More than a quarter of the UK population are affected by depression during their lifetime. For major trauma patients, postinjury depression can result in poorer long-term outcomes, but there is limited evidence regarding outcomes for patients with pre-existing depression. This study investigated the relationship between a diagnosis of depression prior to hospital admission and clinical outcomes after major trauma.

Methods Trauma patients at a UK major trauma center were identified during a 6.5-year period using the Trauma Audit and Research Network database. Patients with Injury Severity Score >15 who did not die in the emergency department (ED) were included. Logistic regression models were used to compare in-hospital mortality (excluding ED), requirement for surgery, and length of stay (LOS) between those with depression and those without.

Results There were 4602 patients included in the study and 6.45% had a diagnosis of depression. Depression was associated with a significant reduction in mortality (OR 0.54, 95% CI 0.30 to 0.91; p=0.026). However, patients with depression were more likely to have longer LOS (OR 124, 95% CI 8.5 to 1831; p<0.001) and intensive care unit LOS (OR 9.69, 95% CI 3.14 to 29.9; p<0.001). Patients with depression were also more likely to undergo surgery (OR 1.36, 95% CI 1.06 to 1.75; p=0.016).

Discussion A pre-existing diagnosis of depression has complex association with clinical outcomes after major trauma, with reduced mortality but longer LOS and higher likelihood of surgical intervention. Further prospective investigations are warranted to inform optimal management strategies for major trauma patients with pre-existing depression.

Level of evidence III.