Physical and mental health

Can you tell me or discuss the relationship between irregular dialysis treatment and its affects on a person’s mental health?

A single line question for an enormous subject!

TJ, though your title asks about ‘physical and mental health’, your actual question hones in on ‘mental’ … so, for better or worse, I have decided to keep primarily to ‘mental’ issues in my answer.

I think there are two primary interpretations of ‘mental health’ contained within your question: (1) mental ability and (2) mental illness. I read the question to be about …

  1. Whether CKD and/or dialysis and its modalities affect brain function (often called ‘cognitive’ function). It would, in this context, be important to know whether cognitive function worsens as CKD worsens … and whether conventional HD further adversely affects or, alternatively, improves cognition from CKD5 … and, finally, if more frequent or longer dialysis (more dialysis) improves or worsens cognition when compared to standard HD.

  2. Whether mental illness is affected either by the various stages of CKD and/or by dialysis … and whether, if affected, this effect is different, between dialysis modalities … or, alternatively, whether mental illness is made worse by CKD and dialysis.

B Does CKD and/or dialysis and its modalities affect cognitive function?[/B]

In a word … ‘yes’ … as CKD progresses, so too do a range of impairments of brain function. This has been much studied.

To quote one or two of the many studies of this area, Hailpern and others from the Albert Einstein College of Medicine in NYC reported a study in JASN in 2007 which looked at 3 factors of brain (cognitive function) in younger adults (20-59), studying nearly 5000 ‘normal’ subjects. They looked at: (a) a simple ‘reaction time’ … = basically how fast a motor response occurs to a painful stimulus (like withdrawing a finger from heat): (b) symbol: digit substitution … = basically how quickly the subjects could replace a set of symbols (eg: letters of the alphabet) with numbers that have been allocated to those symbols: and © serial digit learning … = basically, remembering numbers.

Among the normal subjects were 31 (0.8%) of the whole population with CKD3 (eGFR 30-59 ml/min) and these had significantly impaired learning and concentration skills and impaired visual attention when compared to subjects with a normal eGFR but reaction times were not different.

This suggests that even only modestly impaired levels of eGFR leads to interference with brain function.

In older subjects – this time in a study by Ackerson and others from UCSF in the Journal of Geriatric Medicine, - 825 patients aged 55 and older (mean age 65) with more advanced CKD (eGFR <30 ml/min) showed lower cognitive function scores (generally lower by a factor of 2 x or more) in most areas of brain function: ‘global’ cognition (overall thinking), naming stuff, attention span, executive (planning) skills and memory.

The NKF KDOQI Guidelines note that memory and cognitive function (sustained attention, selective attention, speed of decision-making, short term memory and mental arithmetic are all lower in CKD, and correlate with the level of CKD, worsening as CKD progressed. KDOQI notes a variable degree of improvement after starting dialysis (conventional intermittent dialysis) and further significant trends towards normal after transplantation.

Sleep disturbances are also common in CKD, worsening with the severity of CKD. Poor sleep compounds poor cognitive function. Sleep abnormalities (including restless legs – common in CKD – and myoclonic jerks) can often reach the level of true sleep apnoea with, in some studies, apnoeic episodes occurring in up to 50% of dialysis patents. Not only does this carry morbidity risk (added illness) and mortality risk (increased risk of death) for conventional dialysis patients, but conversion to nocturnal dialysis (Hanly and others from Toronto, NEJM) significantly improves sleep quality and reduces apnoea to the levels seen in the non-dialysis population.

So …

  1. we know cognitive function gets worse as CKD gets worse.
  2. we know that conventional dialysis delivers an ‘effective level of renal function’ equivalent to an eGFR 12-15 ml/min … ie: advanced CKD5 … and holds the dialysis patient st that level.
  3. we know that alternate night and short daily dialysis roughly deliver an equivalent eGFR of 25-30 (ie CKD4)
  4. we know that full 5-6 night/week NHD delivers an eGFR equivalent of abut 40-50 ml/min (ie good CKD3)

It follows that we might therefore expect cognition (and sleep) to improve with ‘better’ dialysis … and indeed they do!

Busko (U Toronto) has reported a study showing a 7% improvement in motor efficiency (for those who like statistics … p 0.02), a 32% improvement in attention span and working memory and a 5% improvement in learning efficiency … likening this, in computer terms, to an improvement in RAM and computer speed but not with any enlargement in the mother board!

So …

To answer the question … does CKD and/or dialysis and its modalities affect cognitive function? … the answer is ‘yes’, they do, but better dialysis (and specifically this means more hours of dialysis) improves that function back towards normal.

(2) Is mental illness affected by dialysis and do the differing modalities differ in their affect?

In a word … ‘yes’ … and a very good paper … which is available on the net at … describes this field well.

In short, this paper looks at depression in CKD and dialysis. The abstract isn’t as helpful as the whole paper (which is quite readable if you should wish to look it up) but it reads, in part, as follows:

Depressive disorders have been shown to be present in 20% to 40% of the population receiving renal-replacement therapy, and this figure may be even higher in the pre-dialysis chronic kidney disease (CKD) population. Psychosocial factors (eg, unemployment, low income, young age, female gender, low-perceived social support, lack of adjustment to the hardship of dialysis, role transitions) make patients vulnerable to depression … … … Screening tools can help in the identification of patients with depressive disorders. Prevention and treatment of depression is crucial because it is strongly associated with several important CKD outcomes. Monitoring the presence of depressive symptoms and enhancing social support should be part of the routine care in the CKD population.

There are clearly other causes of mental illness that either (1) lead to CKD and dialysis – especially those where lithium treatment over many years, especially if accompanied by episodic lithium toxicity, has led to chronic scarring of the ‘interstitium’ (the supportive framework of the tubular regions of the kidney) with resultant ‘interstitial nephritis’ and ‘interstitial fibrosis’ and progressive CKD or (2) make the delivery of dialysis difficult and complex – especially for patients who find confinement in a chair for long and repeated dialysis treatments difficult … like kids with CKD and concurrent autism, Aspergers syndrome or a myriad of psychiatric disorders that make dialysis difficult for patient and staff alike. .

This latter group of patients is often (wrongly) labeled as ‘non-compliant’ … an unfair and pejorative description for a patient who, as a result of a mental illness, finds dialysis doubly difficult and many times more intolerable. Have I a solution to their management? … sadly, no. No more than do others. However, some can manage self-dialysis and, if so, can also do much better at home than in a centre.

There is no way I can do justice to your question in such a superficial overview, TJ, but maybe this answer gets to some of the points your question raises. I do not set myself up as any expert on the management of psychiatric illness in renal replacement therapy patients, and struggle with this as much as the next nephrologist.

However, an open mind and an open heart helps to go some of the way to creating trust and understanding … and trust and understanding opens the door to ‘possibilities’ in management. Finally, those possibilities should (and best) include home dialysis and more dialysis … especially dialysis during sleep … both for those where cognitive function is impaired: it improves with more dialysis; and for those who, finding dialysis intolerable in facility-based care , can sometimes (not always) be better managed and more accepting of renal replacement therapy if it is or can be delivered in their safe haven at home.

I don’t know if this answer has been any help to you at all! In the time I have available to answer questions at this site, it is probably about the best I can offer. There are many, many papers written on these topics - many surprisingly readable and self-explanatory. All are better than my meager effort here!

Hope this helps … !

John Agar

Dr. Agar,

Thank you so much. Your answer helped more than you know. I admit I did phrase the question broadly, but you did a wonderful job. My focus, as you picked up, was on ESRD and mental illness. For the past three years I’ve been working to find appropriate ESRD treatment for individuals with mental illness who have been deemed by the outpatient dialysis clinic as “non-compliant”. Needless to say we have come up against some very tough road blocks in our pursuit. Given the national number of people with mental illness who have been treated with lithium over the years, I’m sure there is a larger population of people who have similar stories of being denied dialysis at the local clinics. I saw you listed a paper in a link in your response, any others you can direct us to?

Again thank you so very much for your help.