Charles-Bonnet Syndrome and other thoughts about physical and mental illness

I thought I’d write about something other than the virus;

I have been reading a book by Psychotherapist and Anthropologist James Davies called ‘Cracked – why psychiatry is doing more harm than good’ It was published in 2013 and I suspect the world has changed little with respect to his message.

You’ll note the clever title (putting aside ‘cracked’ which I don’t like), the ‘harm than good’ being an inverse of the first Hippocratic principle to ‘first, do no harm’ primum non-nocere as they say.

Beyond this deviation and the thesis of the book which describes the many ways in which psychiatry as a science or clinical discipline is messed-up – caught in bed too often with the pharmaceutical industry, for example, was a section relating to the causes of mental illness.

It’s that I want to discuss.

And, yes, I will then explain the title of my blog.

Taking a broad brush approach to health and wellbeing you have two separate families of disease – mental and physical; the latter, associated with a malfunction, disorder, abnormality, aberration of the physical body – when cells, muscles, organs, bones, joints or whatever stop working or, in relation to congenital disease, have never worked.

The fundamental is that if you take a microscope or have enough understanding of DNA or molecular pathways, you can find something wrong, or perhaps something that doesn’t function they way it does in most.

From the very complex yet well understood inherited, single-gene disorders such as Cystic Fibrosis and Huntington’s disease, all the way through to the endlessly complex nature-nurture conditions such as obesity or cancer.

obesity pathway.jpg

Perhaps I have overdone this, suffice it to say, these are the physical conditions, those were surgeons can operate, radiologists can point the way or physicians can offer a tablet or advice.

Moving-on to the less concrete, we have the mental health disorders – depression, anxiety, schizophrenia, bipolar disorder, where much, if not all the diagnosis is based not upon blood tests, x-rays or biopsies but questions and analyses of individuals’ behaviour.

More specifically, depression, is diagnosed on the basis of certain behaviours or responses to carefully worded questions, ‘Have you felt less interested in your usual activities than normal? Are you sleeping too much/too little? How often do you think about ending your life?’

This kind of thing.

There are endless tests you can find online to establish whether you are clinically depressed.

The complicating factor with this and what distinguishes it from say, a dodgy heart value is that if you look inside the person, open them up, send samples to the lab, there is nothing to find that explains the cause of depression; no elevated cholesterol or blood sugar, no over-proliferating cells as in cancer.

And, even though, we, that is me and other doctors have for many years sought to establish an equivalence between mental and physical health, the phraseology we use, the models, at least according to James Davies are wrong.

And this, before I read the book was not something I fully appreciated.

Commonly, when talking about depression, perhaps in an attempt to normalise, to overcome the stigma or to paint a familiar picture, I would use a physical model;

‘Depression is just like diabetes – in your case, the levels of serotonin in your blood are low, as with someone who has diabetes, their levels of insulin are too low and, by giving supplemental insulin we make them better, we do the same with you by prescribing Prozac.’

Or words to that effect.

Acknowledging that in most cases of diabetes, i.e. type two or, maturity onset, the levels of insulin are actually too high.

Anyway, this kind of reductionism worked for me and it provided a useful context with which to write the prescription and send the patient away for a few weeks pending a review.

(I will not mention NICE guidance and the use of talking therapy here.)

The point however is, my explanation is flawed.

The whole concept of depression and serotonin levels is actually just that, an idea, or rather a theory.

If you give SSRI’s (Selective Serotonin Re-Uptake Inhibitors)(Fluoxetine, Citalopram, Sertraline), the drugs will increase the levels of serotonin – a chemical signalling protein found in the brain and throughout the body, and in some instances lead to an improvement in symptoms of depression, yet, and here is the yet, people with depression have not been found to have low levels of serotonin.

It is very difficult to measure the level of chemical neurotransmitters in the brains as, they are in the brain. You can measure the fluid that floats around the brain – Cerebrospinal Fluid, through a spinal tap, and again, this doesn’t show low levels of serotonin in people with depression; indeed, serotonin, like all chemicals within a living system show a normal distribution – some people will have higher levels than others, yet, this doesn’t appear to link with depression. People with lower levels are not necessarily depressed, people with higher levels not necessarily happy.

The point?

Well, it brings into question what we are doing when we prescribe anti-depressants; sure, if they help an individual cope with depression, that is great, although telling stories about high or low chemical levels might be misleading.

Sure, if the ends justify the means; why not? Well, in general, in medicine, as in life, telling people fictions is wrong.

How does all of this take me to Charles Bonnet Syndrome?


For most readers, if you haven’t given-up already and Googled, this is a syndrome named after the Swiss lawyer/naturalist, Charles Bonnet. (Note, at least as far as I know, the ‘Bonnet’ is said ‘Bonnay’ rather than the way we pronounce a fancy hat), also, the condition is usually abbreviated to ‘CBS’ which I will do to save myself typing.

What is CBS?

It is a condition where people experience visual hallucinations, yet do not have a mental illness.

You see, if people hallucinate, usually, this is either the results of a transient state – perhaps eating magic mushrooms or associated with illness – delirium or, something more long-lasting such as psychosis as in schizophrenia.

The former – the mushrooms are what you might consider a psychiatric manifestation of a physical situation i.e. eating a poison and the effects this has on the brain, the latter, schizophrenia, sits in the mental health realm, with a theory which says that too much dopamine is destabilising the brains of individuals – this, despite the lack of evidence for people with schizophrenia having too high levels of dopamine (the theoretical causative neurotransmitter in the condition)

It’s all a bit of a mess is it not?

If you have too much LSD or Psilocybin, you are likely to be treated by a medical doctor;

you will be observed and once the effects have worn-off you will be sent on your way.

If you have schizophrenia the outcome will often be different, you may receive treatment with an anti-psychotic, you might be subjected to a section under the mental health act – potentially detained in a psychiatric hospital against your will; you might be given injections and all sorts of things – although less today than 20 years ago.

It is kind of interesting, for, medical doctors can do all sorts of things to people as part of treatment – send them under anaesthetic, cut through the skin, amputate, prescribe all sorts of medicines, yet, psychiatrist alone have the unique capacity to hospitalise someone against their will for months on end.

Mental and physical.

I have long considered the two to be one; like the way I struggle with ‘health’ and ‘social care’ preferring ‘care’ – for me, it is not ‘mental’ and ‘physical’ health but, ‘health’

Maybe I am not adequately reductionist.

The problem with CBS is that it is a physical disorder with psychiatric symptoms.

CBS is theorised to develop in those who have abnormalities to their vision; cataracts, macular degeneration, optic atrophy, that kind of thing.

You see, as the philosopher – I think it was maybe Schopenhauer said, life is an hallucination.

Apologies for getting a little abstract, it all coincides.

What is meant in this statement is that we don’t really see things, rather, images are perceived by our eyes and chemical processes in our brain create a sense of something.

You know that photo of the floating bin? That kind of thing.

floating bin.jpg

We see what we believe, and we believe what we see.

Out optic blind-spots continuously adapt to provide us with a seamless sense of reality, only becoming real when we reverse into a wall that we didn’t see.

The most common presentation for CBS is seeing people or animals in their room. Most frequently children or tiny creatures are seen, miniatures they know can’t possibly be present yet appear real. At other times, they perceive patterns or shapes, lines, zigzags or lights.

You see, if a 90 year old describes the cute dog that sits in their living room at mealtimes and never barks to their doctor or family, the initial suspicion is that they are unwell – and, given the increasing frequency of dementia as people age, the suspicion of this condition affecting grandma or granddad.

Sometimes this is correct, for, some types of dementia result in visual hallucinations.

The thing about dementia and CBS is that their causes are very different; in general, the former, dementia, is caused by (again it is theorised) deficiencies in the neurotransmitter acetylcholine caused by brain damage – either from the effects of mini-strokes (vascular dementia) or abnormal protein deposition (Alzheimer’s disease).

The latter, CBS is nothing to do with the brain, beyond it doing what it always does, i.e. take what the eyes perceive and creates an image.

In CBS it is the eyes that are diseased, not the brain.

And this is the thing.

If you are lucky and your doctor is aware of CBS, they may consider this as a possibility and explore the diagnosis – refer you for eye assessments and proceed down the relevant management route, specifically, fixing glasses, removing cataracts, ensuring adequate lighting;

If, however your doctor hasn’t learned about this condition they may get it wrong, assume you are developing dementia or another psychotic disorder and prescribe antipsychotics (I have written about these drugs and their potential complications here).

And, this all takes me back to depression and diabetes. (There is a separate causal link, in that people who have depression are more likely to have diabetes and vice versa.)

Should we continue to split the world into medical and mental?

Should we continue to utilise false analogies with our patients?

What happens when a mental disorder is construed as a physical one (this the whole topic of functional disorders, also described here, or, if you want a good book, check out ‘It’s all in your head’.

What happens conversely if your physical disorder is treated as mental? We see this all the time. Whether antipsychotics prescribed instead of better lighting or sedatives used to calm those living with dementia rather than establishing the person is in pain, fearful or just feeling bad. (People who had dementia have off days too).

Maybe I have merely demonstrated the complexity and, I suspect this is my point.

Reductionist principles of this does this and that happens, are really no way to explain the incredible sophistication of health and disease – it may work for children (I suspect not) and ultimately leads to lack of trust and clinical nihilism.

You remember the poem Mending Wall, so loved by Mr T?

Well, this is perhaps where I will leave this story;

Walls don’t contribute to good care.

The systematic barriers between health and social care, physical and mental health perhaps benefit some people, for the greater part, they just delay our understanding and effectiveness.

There is nothing much as good as a resolute, ‘I don’t know’ to help us shine light into the darkness.

fish field stars.jpg

Published by rodkersh1948

Trying to understand the world, one emotion at a time.

2 thoughts on “Charles-Bonnet Syndrome and other thoughts about physical and mental illness

  1. So with ARMD and cataracts both in both eyes, CBS definite possibility and know of people who find it very frightening. Also hallucinations in dementia can be very upsetting and frightening – know of a lady who said there was ‘ a man’ waiting outside and she was agitated { the angle of her chair to the window was changed was changed and disney film and favourite tv recordings helped to distract.}.
    Prior to advanced medical knowledge and skills, political manoevering {?} and financial policy, health and social care were as one.
    Physical and mental health are indivisible in their impact one upon the other , in one person. Treat the person?

    Liked by 1 person

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.

%d bloggers like this: