Depression and Cognitive Impairment in Peritoneal Dialysis: A Multicenter Cross-sectional Study

Abstract

Background: Depression and cognitive impairment have been identified as independent risk factors for mortality in peritoneal dialysis (PD) patients. The relationship between depression and global and specific cognitive functions in PD patients was investigated in this study.

Study design: Multicenter cross-sectional study.

Setting & participants: 458 clinically stable patients, drawn from 5 PD units, who performed PD for at least 3 months were enrolled.

Predictor: Depression, defined as depression severity index score > 0.5 using the Zung Self-rating Depression Scale.

Outcomes: Global and specific cognitive impairment. Global cognitive function was measured using the Modified Mini-Mental State Examination (3MS), Trail-Making Test forms A and B for executive function, and subtests of the Battery for the Assessment of Neuropsychological Status for immediate and delayed memory, visuospatial skills, and language ability.

Results: Prevalences of depression and cognitive impairment evaluated by the 3MS were 52% and 28.4%, respectively. Patients with mild or moderate/severe depression had higher prevalences of general cognitive impairment, executive dysfunction, and impaired immediate and delayed memory. After adjusting for demographics, comorbid conditions, and clinical parameters, depression scores were independently associated with lower 3MS scores, lower immediate and delayed memory and language ability scores, and longer completion times of Trails A and B. Even mild depression was independently associated with higher risk for cognitive impairment, executive dysfunction, and impaired immediate and delayed memory after multivariable adjustments.

Limitations: The causal relationship between depression and cognitive impairment could not be determined, and the potential copathogenesis behind depression and cognitive impairment was not fully investigated.

Conclusions: Even mild depression is closely associated with global and specific cognitive impairment in PD patients.

Keywords: Peritoneal dialysis (PD); chronic kidney disease (CKD); cognitive dysfunction; cognitive impairment; depression; end-stage renal disease (ESRD); executive dysfunction; executive impairment.