Depression ups risk of poor kidney transplant outcome

[okarol]

Depression ups risk of poor kidney transplant outcome

1 hour, 41 minutes ago

NEW YORK (Reuters Health) - Among kidney transplant recipients, depression doubles the risk of kidney failure, return to dialysis therapy, and death, new research indicates.

"Concerns about transplant rejection, fear of infection, readjustment to everyday life, and use of immunosuppressive medications, with frequent and often severe adverse effects" can lead to emotional problems in the early years after kidney transplantation, the research team notes in the current issue of the American Journal of Kidney Diseases.

However, the consequences of developing depression in this patient population are unclear.

To look into this issue, Dr. Fabienne Dobbels from Katholieke Universiteit Leuven in Belgium and associates identified 47,899 patients who had a kidney transplanted between 1995 and 2003.

Records showed that the cumulative incidence of depression was roughly 7 percent 1 year after kidney transplantation; it was 11 percent and 13 percent, respectively, 2 and 3 years post-transplantation.

Kidney failure occurred in 19 percent of patients, 8 percent died with a functioning kidney, and approximately 11 percent had to go back to dialysis therapy,.

According to the researchers, depression was associated with about a two-fold increased risk of each of these adverse outcomes.

"Depression after kidney transplantation is a serious condition associated with poor clinical outcomes," Dobbels and colleagues conclude. Therefore, depression screening and periodic reassessment "is of crucial importance to determine which patients should be referred for specialized mental health treatment."

SOURCE: American Journal of Kidney Diseases, May 2008.

http://news.yahoo.com/s/nm/20080526/hl_nm/depression_kidney_dc_1

[stauffenberg]

Like most epidemiological studies, this one suffers from the enormous difficulty of separating the confounding variables with threaten to make the study worthless.  Thus for example it may be that the patients with a transplant who are most likely to be depressed are also those whose transplants are doing poorly, and the poor functioning of their transplants is the main cause of their being depressed, not the effect of their being depressed.  This would cause a correlation between depression and graft failure to appear in the data, but the hypothesis of depression having something to do with the failure would be totally misleading. 

Also, there may be a correlation between patients being depressed and their deciding not to take their medications.  Or perhaps it is those who cannot afford to pay for their medications who are most likely to be depressed.  In all these possibilities, depression changes its role from being a cause of the graft failure to just being a correlate of it with no direct causal role.

[okarol]

This article does not discuss the alternative, dialysis, which also can have a high incidence of depression present in patients.
ESRD is just not a easy road.

[pelagia]

Like most epidemiological studies, this one suffers from the enormous difficulty of separating the confounding variables with threaten to make the study worthless.

Such a study is far from worthless.  It sets the stage for further exploration of the relationships between depression and transplant failure.  It is very difficult to design good hypothesis-driven studies without preliminary data or observations.  The authors mentioned in the article below analyzed Medicare records to determine if there were relationships among graft failure, depression, and a suite of other factors.  In my field, we call it "data-mining." Such an approach makes it possible to eliminate some factors as likely unimportant, while retaining others as potentially very important in future studies.  Not everything can be tested experimentally -- the cost of the research would be prohibitive.