Depressed chronic kidney disease patients more likely to face complications

Patients with chronic kidney disease who have been diagnosed with depression are twice as likely to be hospitalized, progress to long-term dialysis treatments or die within a year as those who are not depressed, UT Southwestern Medical Center researchers have found.

In the study, appearing in the May 19 issue of the Journal of the American Medical Association, researchers monitored for one year 267 patients with chronic kidney disease - 56 of them with a diagnosis of a current major depressive episode, referred to here as depression, based on the Diagnostic and Statistical Manual of Mental Disorders 4th edition (DSM-IV).

Nearly 61 percent of patients with depression compared to 44 percent without depression either died, progressed to long-term dialysis, or were hospitalized within a year of observation; 55 percent of depressed patients were hospitalized compared to 40 percent of patients who were not depressed; 27 percent of depressed patients needed to start regular dialysis treatments compared to 11 percent without depression; and 9 percent of depressed individuals died compared to 6 percent without depression.

"Chronic kidney disease patients with depression have poorer health outcomes than those without depression, even after adjusting for other factors that determine poor outcomes in these patients, such as other medical diseases, anemia and low albumin levels," said Dr. Susan Hedayati, assistant professor of internal medicine at UT Southwestern, staff nephrologist at the Dallas VA Medical Center and lead author of the study. "Clinicians should consider screening chronic kidney disease patients for depression, especially since depression is also associated with poor quality of life."

Twenty-six million people in America have chronic kidney disease and millions more are at an increased risk, according to the National Kidney Foundation. If treatment does not begin early, the condition progresses to end-stage renal disease. At that point, a patient's kidneys have failed to the point where dialysis - a filtering of toxic chemicals in the blood and removal of fluid to help control blood pressure - or a kidney transplant is needed.

In 2007 an estimated $24 billion, about 6 percent of the entire Medicare budget, was spent on dialysis-related health care in patients with chronic kidney disease, according to the U.S. Renal Data System 2009 Annual Report.

This JAMA study is the first to look at outcomes as they relate to an association between chronic kidney disease and depression in patients prior to starting regular dialysis. In previous reports, Dr. Hedayati has found that one in five chronic kidney disease patients is depressed before beginning long-term dialysis therapy and that patients already on dialysis who have been diagnosed with depression are nearly twice as likely to be hospitalized or die within a year than those who are not depressed.

For the current study from May 2005 to November 2006, researchers invited patients at the Dallas VA Medical Center who were visiting the clinic for chronic kidney disease appointments to join the study. Patients who agreed to participate then underwent a structured clinical interview to determine if they had a current major depressive episode, based on the DSM-IV definition which is considered the gold-standard in evaluating depression.

Fifty-six patients were found to be depressed. The mean age of patients was about 65; two were women; and nearly 56 percent were white. All patients were veterans.

The association between chronic kidney disease, depression and poorer health outcomes held after adjusting for age, race and other current medical conditions.

"Our results support the need for well-designed clinical trials to investigate if antidepressant treatment is efficacious and safe in this vulnerable population. Patients with advanced kidney disease have been previously excluded from larger randomized trials of antidepressant medication treatment," said Dr. Hedayati, who is now conducting the Chronic Kidney Disease Antidepressant Sertraline Trial (CAST) to determine whether antidepressant medication would be tolerated in kidney-disease patients and whether such treatments can improve depression and quality of life.