First, there is the difficulty in measuring depression, which has resulted in varying reports on the prevalence of depression in ESRD patients. There have been inconsistent results from multiple studies, and as Hedayati summarized, this lack of consistency likely reflects different disease severity, populations assessed at different time points since starting dialysis, and different depression measures. Kimmel placed the prevalence between 5-10%. In the large Dialysis Outcomes and Practice Patterns Study (DOPPS), the prevalence of physician-diagnosed depression was 14% and probable depression was 43%.
Which instrument is used to assess depression? The DSM-IV is considered the appropriate tool for a clinical diagnosis of depression and is administered by a trained interviewer, rather than being filled out by a patient. While other instruments have been used, Hedayati et al. found that a clinical DSM IV-based diagnosis of depression is a stronger predictor of outcomes compared with self-report scales.
Compounding these challenges is the difficulty in distinguishing between depression and physical symptoms of ESRD and uremia. Other methodologic issues: applying the instruments to varying demographic populations across time (at the initiation of dialysis versus several years later), race, and geography.
Ultimately, what is needed are well-designed, longitudinal, large studies to determine the association between depression and mortality and whether intervention and treatment of depression, whether through greater screening efforts, treatment with anti-depressants, or cognitive behavioral therapy approaches, will impact outcomes such as lowering mortality in patients with ESRD.
Posted by Julie Paik M.D.