Delirium, depression, and long-term cognition

Objectives: We examined whether preadmission history of depression is associated with less delirium/coma-free (DCF) days, worse 1-year depression severity and cognitive impairment. Design and measurements: A health proxy reported history of depression. Separate models examined the effect of preadmission history of depression on: (a) intensive care unit (ICU) course, measured as DCF days; (b) depression symptom severity at 3 and 12 months, measured by the Beck Depression Inventory-II (BDI-II); and (c) cognitive performance at 3 and 12 months, measured by the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) global score. Setting and participants: Patients admitted to the medical/surgical ICU services were eligible. Results: Of 821 subjects eligible at enrollment, 261 (33%) had preadmission history of depression. After adjusting for covariates, preadmission history of depression was not associated with less DCF days (OR 0.78, 95% CI, 0.59-1.03 p = 0.077). A prior history of depression was associated with higher BDI-II scores at 3 and 12 months (3 months OR 2.15, 95% CI, 1.42-3.24 p = <0.001; 12 months OR 1.89, 95% CI, 1.24-2.87 p = 0.003). We did not observe an association between preadmission history of depression and cognitive performance at either 3 or 12 months (3 months beta coefficient -0.04, 95% CI, -2.70-2.62 p = 0.97; 12 months 1.5, 95% CI, -1.26-4.26 p = 0.28). Conclusion: Patients with a depression history prior to ICU stay exhibit a greater severity of depressive symptoms in the year after hospitalization.