I’ve come across a 2007 study review paper by Suzanne Watnick, MD. It’s called Depression in the End-stage Renal Disease Population on Dialysis, and you can see it here. (“End-stage” in this context simply means the complete or almost complete loss of kidney function with no expectation that it will return. It does not imply imminent death. People can live for years and even decades on dialysis after receiving a diagnosis of end-stage renal disease.)
Dr. Watnick discusses the significance of depression in the kidney failure population, and one of her conclusions is that: “Depression is a common and under-recognized disorder in the dialysis population.” She concludes that: “Cases of depression have higher rates of morbidity and mortality and the impact of depression on survival in the dialysis population requires further study.”
She does acknowledge that her conclusions rest on “small case series and randomized control trials…,” and states that: “All of these studies showed improvement in depressive symptoms over short-term periods of six to 12 weeks, but long-term follow-up was not reported.”
Nevertheless, Dr. Watnick offers the following “basic recommendations:”
“• start antidepressant medications at low doses;
• increase medication dose at three- to four-weekly intervals as necessary;
• consider the institution of an exercise program;
• include an educational component targeting depression in the setting of ESRD to help the patient understand his/her diagnosis; and
• if the initial treatment does not help, consider referral to a psychiatrist for further counseling and treatment—including psychotherapy and cognitive behavioral interventions.”
In my view, Dr. Watnick’s recommendation to administer antidepressant drugs on the basis of short-term studies is questionable. She did admittedly call for further research, but it might have been prudent to delay her recommendations until the results of such research were available.
Happily, we now have some long-term [5-year] research – Correlation of antidepressive agents and the mortality of end-stage renal disease, by Tsai et al, which you can see here. This is a database search (not a randomized controlled trial), and so results have to be interpreted with caution.
The results of this study, which included data on 2,312 patients, were:
1. Diagnosis of depression did not influence mortality rate (mortality rate in patients with depression: 26.5%; mortality rate in patients without depression: 26.2%.
2. Patients who had been given antidepressants had a significantly higher mortality rate (mortality rate: 32.3%) than those who had not (mortality rate: 24.5%) The likelihood that a difference of such magnitude would have occurred by chance is less than one in a thousand.
The authors do point out that this doesn’t prove that the antidepressants were causing the excess deaths. (It might be that the drugs were being given to the people who were in poorer health to begin with.) But by the same token, it doesn’t rule out the possibility of a toxic effect. In addition, it certainly constitutes a significant challenge to Dr. Watnick’s contention that cases of depression have higher rates of mortality, and her recommendation that depressed individuals be given antidepressant drugs.
People who are on dialysis have markedly diminished ability to clear toxic by-products from the blood stream. In dialysis circles, it is widely stated that the clearing power of regular (i.e. 3-times-weekly) dialysis is approximately 10%-15% as effective as a pair of functioning kidneys. So it is within the realm of possibility that toxic by-products from antidepressants could accumulate in the blood stream and have a detrimental effect. Dr. Watnick acknowledges this factor but suggests merely that “…the starting dose should be as low as possible and increased slowly if needed.”
The general problem is that antidepressants are being routinely prescribed as the first line response to any indication of despondency in an increasingly wide range of situations.