A preliminary investigation of depression and kidney functioning in patients with chronic kidney disease.

BACKGROUND: The incidence and prevalence of Chronic Kidney Disease (CKD) is growing rapidly. Understanding the factors associated with declining renal function is of clinical significance. The current study's main goal was to identify variables that could predict decline in glomerular filtration rate (GFR) over time in outpatients with varying stages of CKD.
METHODS: Seventy CKD patients completed psychological questionnaires and medical variables were extracted from the medical charts. Follow-up GFR was collected 6 months later. CKD patients with elevated depression scores were compared to patients with subclinical depression on medical and psychological variables.
RESULTS: Average Beck Depression Inventory (BDI) score was 10.0 ± 7.8, placing the mean below the cut-off for clinical elevation. GFR was significantly different for the two groups (nondepressed, 40.0 ± 11.3 vs. depressed 29.6 ± 8.9; p < 0.05). Similarly, patients with elevated depression scores reported lower quality of life (Short Form 36 Health Survey; p < 0.05) inferior social support (Interpersonal Support Evaluation List; p < 0.05), and worse community integration (Community Integration Questionnaire; p < 0.05). Utilizing a regression, with a model correcting for baseline GFR, the BDI explained 19% of the variance in GFR score (t = -2.0, p < 0.05) for subjects with decreased GFR.
CONCLUSIONS: Increased levels of preexisting depression were associated with inferior quality of life, social support and kidney functioning. Depression scores explained a significant amount of variance in GFR scores at 6 months even when corrected for baseline variability. Elevated depression scores are prevalent in CKD populations and further research on the impact of depression interventions is warranted.