Abstract / Summary
ABSTRACT Background and Objective: Cognitive impairment is a prevalent and under-recognized phenomenon associated with chronic kidney disease (CKD). It becomes more common as kidney function declines, peaking among patients on dialysis. However, few studies have systematically compared the cognitive profile and clinical implications of cognitive dysfunction between non-dialysis CKD and dialysis-dependent kidney failure. This narrative review aimed to collate and compare recent findings regarding the clinical characteristics of cognitive impairment associated with non-dialysis CKD and dialysis. Methods: A structured narrative review was performed. Databases searched included PubMed/MEDLINE, Scopus, Web of Science and Google Scholar (1 January 2020 to 15 May 2026). Eligible reports included cognitive performance data in adults with non-dialysis chronic kidney disease (CKD), haemodialysis (HD) or peritoneal dialysis (PD). Results: Pooled prevalence is approximately 32% in non-dialysis chronic kidney disease (CKD), 39% in peritoneal dialysis (PD) and 53% in haemodialysis (HD). Executive function, attention and processing speed are most commonly impaired, with relative preservation of memory and language until later stages. Accumulation of uremic toxins, small-vessel cerebrovascular disease, inflammation, oxidative stress and Blood–Brain-Barrier disruption contributes to cognitive decline in kidney disease. In HD, recurrent intradialytic hypotension and osmotic stress are additional accelerators of white-matter injury and cognitive decline with increased temporal variability. Cognitive impairment is an independent predictor of non-adherence to treatment, low health-related quality of life, hospitalisation and mortality. Conclusion: Cognitive impairment represents a clinical challenge in chronic kidney disease. Current evidence suggests that routine screening with sensitive cognitive tests and multidisciplinary management can help mitigate cognitive decline in these patients. There is a need for future research comparing longitudinal cognitive profiles, cognitive batteries specific for CKD, and interventional trials targeting potentially modifiable dialysis-related factors. Keywords: Chronic kidney disease; Cognitive impairment; Haemodialysis; Peritoneal dialysis; Kidney–brain axis; Uremic toxins; Neuroinflammation