Depression Symptoms Do Not Worsen over Time in a Cohort of Patients with CKD

Key Points In a cohort of individuals with CKD and a high prevalence of depression and antidepressant use, depression symptoms did not worsen over time. This finding was consistent across all levels of eGFR impairment, including those who initiated dialysis. There were no differences in changes in depressive symptoms over time between individuals with CKD of any stage and those without CKD. Background The prevalence of depression is high in the CKD (20%–40%) and dialysis (30%–50%) populations. Less is known about how depressive symptoms change over time in patients with CKD. Methods Participants in the Brain in Kidney Disease cohort study completed a depressive symptom questionnaire (Patient Health Questionnaire-9 [PHQ-9]) and serum creatinine testing annually. We used linear mixed-effects models to examine changes in PHQ-9 scores over time and compared rates of change between participants with different ranges of eGFR impairment and those with normal eGFR. Results At baseline, 147 participants had normal eGFR, 424 had impaired eGFR without dialysis dependence, and 31% reported a diagnosis of depression, with a mean baseline PHQ-9 score of 4.3. Participants were followed for up to 5 years. After adjustment for factors associated with depression, mean PHQ-9 scores decreased (improved) by 0.25 points per year (95% confidence interval [CI], 0.07 to 0.42) among participants with normal eGFR (>60 ml/min per 1.73 m 2 ) and by 0.35 points (95% CI, 0.14 to 0.56), 0.30 points (95% CI, 0.13 to 0.46), and 0.42 points (95% CI, 0.06 to 0.77) among participants with eGFR 45–59 ml/min per 1.73 m 2 , with eGFR 30–44 ml/min per 1.73 m 2 , and who developed dialysis dependence, respectively. PHQ-9 scores among participants with eGFR <30 ml/min per 1.73 m 2 did not change significantly. We did not observe any statistically significant differences in mean change in PHQ-9 scores between participants with any degree of eGFR impairment and those with normal eGFR, nor between participants with dialysis dependence and those with eGFR of ≤15 ml/min per 1.73 m 2 . Participants with a PHQ-9 score ≥5 had 80% greater odds of immediate study attrition than participants with a PHQ-9 score of 0–4. Conclusions The mean PHQ-9 scores of participants were largely stable over time, and we observed no differences in change in PHQ-9 scores between those with impaired eGFR and those with normal eGFR.