Interesting read and one I find myself in many ways aligned with, in particular the idea that schizophrenia is not synonymous with psychosis.
I hesitate with the idea of 'brain failure' itself though. In organ failure, the hardware is genuinely broken. But in most psychosis, the brain seems to be running, just in a mis-calibrated way at the level of various networks/processes. For example, with aberrant salience, the salience process isn't necessarily 'broken' at a hardware level (even if there are correlates of that miscalibration) - it's just mis-calibrated (and can be re-calibrated).
The cause of that mis-calibration, are not necessarily just due to the brain malfunctioning either (i.e. trauma is gonna lead to excessive salience on trauma related percepts, and potentially lead to 'psychotic' symptoms - the brain isn't failing here and wasn't the primary source of the psychotic symptom?).
I think psychosis broadly represents a breakdown in the alignment between a person's internal model of reality and the shared reality they inhabit. Most psychiatric disorders involve some version of that drift: depression, anxiety, trauma etc all involve internal models that have diverged from 'the norm' resulting in dysfunction within a shared world. When that misalignment increases, with severity of illness - it makes sense that one might develop psychotic symptoms, as the internal models begin to influence even perception. It's no wonder that, psychotic symptoms in mood disorder - are often mood congruent. They related to the extent of the misalignment, and not necessarily to a broken physical process.
This also links to your footnote on subclinical psychotic experiences. If it's a continuum of self-world misalignment, it's unsurprising that such experiences are common. Most people drift a little, some more, a few - enough that dysfunction arises and we call it a disorder.
I agree that "psychosis broadly represents a breakdown in the alignment between a person's internal model of reality and the shared reality they inhabit." Earlier versions of this essay drew an explicit parallel with heart failure that perhaps I should have kept.
We think of heart failure as impaired LV function or reduced cardiac output, but it's actually the inability of the heart to meet the body's metabolic demand. There is high-output heart failure, when cardiac output goes up! So the mismatch is the key, not any specific pathology within the organ.
The analogy is that the brain's purpose is to match brain output (behavior) to environmental demands. An internal world model is a mechanism for this, and psychosis results from the mismatch.
Thanks for your comment, and I realize I was not clear enough about this. I am a CL psychiatrist and spent years advocating for delirium as acute brain failure, but I now think it's insufficient or incorrect. There are a lot of ways that delirium does NOT fit as acute brain failure:
1. delirium as ABF implies that the brain's main function is something like paying attention or being awake, which seems odd
2. delirium often produces psychosis as it worsens. How do we think about this?
3. there's no "primary," spontaneous, intrinsic delirium; it's essentially always secondary to some other condition. This is different than heart/kidney/liver failure.
4. it is very rare in non-elderly, again unlike heart/kidney/liver failure. 24-year-olds present with auto-immune heart or kidney failure, for instance. What is the equivalent in the brain? (it's psychosis or catatonia)
5. acute organ failure should turn into chronic organ failure, presumably. There is no chronic delirium, and delirium does not "turn into" dementia. They're separate processes.
6. delirium famously waxes and wanes over the course of hours; this again seems unlike heart or kidney failure
As I gestured at, I think you could say that there are two types of brain failure: preserved consciousness (psychosis) and altered consciousness (delirium, vegetative states, some dementia). I think you could also draw an analogy between level of consciousness/alertness and heart rate, making altered consciousness like arrhythmias. The physiologies of CNS arousal and cardiovascular overlap quite a bit. This makes delirium more like atrial fibrillation, which also has a lot of nice parallels when you think about it.
I'm always glad to see a post from you, in my inbox!
Two big questions:
1. While everything you wrote makes perfect sense and it's hard to see how someone would come to a different conclusion... Is there a consequentially different status quo you're arguing against or are you advocating a slight difference in semantics and framing (or simply explaining it to a lay-audience? You begin by saying "The DSM and ICD describe psychotic symptoms only in relation to schizophrenia and similar disorders, implying that one is a “reasonable proxy” for the other," before giving many counter-examples - are other psychiatrists commonly conflating psychosis and schizophrenia, in practice?
2. Should this interpretation apply to the majority or the minority of psychiatric symptoms and possible pathophysiologies? At the end, you list "poor motivation, flat emotions, [and] social withdrawal" as symptoms of schizophrenia, but, like psychosis, all three are also possible symptoms of other diagnoses or "a sign they’re getting worse."
This also made me think about "computational psychiatry:" Psychosis is a dramatic failure of perceptual-cognitive predictive processing, but there's also the OTHER "Dark Room Problem" - the main "Dark Room Problem" is the question of why, if predictive coding controls behavior, a healthy mind trying to minimize prediction error doesn't use a "dark room" to minimize stimulus; the OTHER "Dark Room Problem," for which I haven't found a good explanation, is that we KNOW that a variety of unhealthy minds minimize stimulus, in varying degrees!
1. There is something of a disconnect between how a) how the DSM and ICD present these conditions 2) how psychiatrists think about them 3) how other medical professionals think about them (I certainly get consults for "schizophrenia" in an elderly patient with dementia and psychosis, for instance) and 4) how the lay public thinks about them. And you often read research articles that use psychosis and schizophrenia almost interchangeably, though of course many others distinguish them. The modern view of schizophrenia is of multiple symptom clusters, only one of which is "positive symptoms" aka psychosis. We have concepts like "primary psychosis," affective psychosis, secondary psychosis, etc. Which imply that psychosis really belongs to schizophrenia, and other instances of psychosis are somehow second class citizens. I think it's simpler to see psychosis as the final common pathway of all of these, including schizophrenia.
2. I think there is probably some physiological overlap between negative symptoms of schizophrenia, some types of depression, some personality types, etc.
That is a very interesting thought - amotivation and anhedonia as examples of the Dark Room Problem in action!!
Great question. I don't think they are really psychosis in the usual sense. I think they're a form of dissociation (what is that? I don't know) or an abnormally intense emotion. I'm mulling over an aphorism, with apologies to Arthur C. Clarke: "Any sufficiently extreme emotion is indistinguishable from psychosis."
FYI, the diagrams you linked seem to be doing that .svg thing where most of the important info blends into the background of the page, at least on mobile.
Interesting read and one I find myself in many ways aligned with, in particular the idea that schizophrenia is not synonymous with psychosis.
I hesitate with the idea of 'brain failure' itself though. In organ failure, the hardware is genuinely broken. But in most psychosis, the brain seems to be running, just in a mis-calibrated way at the level of various networks/processes. For example, with aberrant salience, the salience process isn't necessarily 'broken' at a hardware level (even if there are correlates of that miscalibration) - it's just mis-calibrated (and can be re-calibrated).
The cause of that mis-calibration, are not necessarily just due to the brain malfunctioning either (i.e. trauma is gonna lead to excessive salience on trauma related percepts, and potentially lead to 'psychotic' symptoms - the brain isn't failing here and wasn't the primary source of the psychotic symptom?).
I think psychosis broadly represents a breakdown in the alignment between a person's internal model of reality and the shared reality they inhabit. Most psychiatric disorders involve some version of that drift: depression, anxiety, trauma etc all involve internal models that have diverged from 'the norm' resulting in dysfunction within a shared world. When that misalignment increases, with severity of illness - it makes sense that one might develop psychotic symptoms, as the internal models begin to influence even perception. It's no wonder that, psychotic symptoms in mood disorder - are often mood congruent. They related to the extent of the misalignment, and not necessarily to a broken physical process.
This also links to your footnote on subclinical psychotic experiences. If it's a continuum of self-world misalignment, it's unsurprising that such experiences are common. Most people drift a little, some more, a few - enough that dysfunction arises and we call it a disorder.
I agree that "psychosis broadly represents a breakdown in the alignment between a person's internal model of reality and the shared reality they inhabit." Earlier versions of this essay drew an explicit parallel with heart failure that perhaps I should have kept.
We think of heart failure as impaired LV function or reduced cardiac output, but it's actually the inability of the heart to meet the body's metabolic demand. There is high-output heart failure, when cardiac output goes up! So the mismatch is the key, not any specific pathology within the organ.
The analogy is that the brain's purpose is to match brain output (behavior) to environmental demands. An internal world model is a mechanism for this, and psychosis results from the mismatch.
Why is delirium not acute brain failure it fits it perfectly?
Thanks for your comment, and I realize I was not clear enough about this. I am a CL psychiatrist and spent years advocating for delirium as acute brain failure, but I now think it's insufficient or incorrect. There are a lot of ways that delirium does NOT fit as acute brain failure:
1. delirium as ABF implies that the brain's main function is something like paying attention or being awake, which seems odd
2. delirium often produces psychosis as it worsens. How do we think about this?
3. there's no "primary," spontaneous, intrinsic delirium; it's essentially always secondary to some other condition. This is different than heart/kidney/liver failure.
4. it is very rare in non-elderly, again unlike heart/kidney/liver failure. 24-year-olds present with auto-immune heart or kidney failure, for instance. What is the equivalent in the brain? (it's psychosis or catatonia)
5. acute organ failure should turn into chronic organ failure, presumably. There is no chronic delirium, and delirium does not "turn into" dementia. They're separate processes.
6. delirium famously waxes and wanes over the course of hours; this again seems unlike heart or kidney failure
As I gestured at, I think you could say that there are two types of brain failure: preserved consciousness (psychosis) and altered consciousness (delirium, vegetative states, some dementia). I think you could also draw an analogy between level of consciousness/alertness and heart rate, making altered consciousness like arrhythmias. The physiologies of CNS arousal and cardiovascular overlap quite a bit. This makes delirium more like atrial fibrillation, which also has a lot of nice parallels when you think about it.
I'm always glad to see a post from you, in my inbox!
Two big questions:
1. While everything you wrote makes perfect sense and it's hard to see how someone would come to a different conclusion... Is there a consequentially different status quo you're arguing against or are you advocating a slight difference in semantics and framing (or simply explaining it to a lay-audience? You begin by saying "The DSM and ICD describe psychotic symptoms only in relation to schizophrenia and similar disorders, implying that one is a “reasonable proxy” for the other," before giving many counter-examples - are other psychiatrists commonly conflating psychosis and schizophrenia, in practice?
2. Should this interpretation apply to the majority or the minority of psychiatric symptoms and possible pathophysiologies? At the end, you list "poor motivation, flat emotions, [and] social withdrawal" as symptoms of schizophrenia, but, like psychosis, all three are also possible symptoms of other diagnoses or "a sign they’re getting worse."
This also made me think about "computational psychiatry:" Psychosis is a dramatic failure of perceptual-cognitive predictive processing, but there's also the OTHER "Dark Room Problem" - the main "Dark Room Problem" is the question of why, if predictive coding controls behavior, a healthy mind trying to minimize prediction error doesn't use a "dark room" to minimize stimulus; the OTHER "Dark Room Problem," for which I haven't found a good explanation, is that we KNOW that a variety of unhealthy minds minimize stimulus, in varying degrees!
(I love the article's subtitle, by the way)
Thank you!
1. There is something of a disconnect between how a) how the DSM and ICD present these conditions 2) how psychiatrists think about them 3) how other medical professionals think about them (I certainly get consults for "schizophrenia" in an elderly patient with dementia and psychosis, for instance) and 4) how the lay public thinks about them. And you often read research articles that use psychosis and schizophrenia almost interchangeably, though of course many others distinguish them. The modern view of schizophrenia is of multiple symptom clusters, only one of which is "positive symptoms" aka psychosis. We have concepts like "primary psychosis," affective psychosis, secondary psychosis, etc. Which imply that psychosis really belongs to schizophrenia, and other instances of psychosis are somehow second class citizens. I think it's simpler to see psychosis as the final common pathway of all of these, including schizophrenia.
2. I think there is probably some physiological overlap between negative symptoms of schizophrenia, some types of depression, some personality types, etc.
That is a very interesting thought - amotivation and anhedonia as examples of the Dark Room Problem in action!!
What do think about so called "brief psychotic episodes" in BPD?
Great question. I don't think they are really psychosis in the usual sense. I think they're a form of dissociation (what is that? I don't know) or an abnormally intense emotion. I'm mulling over an aphorism, with apologies to Arthur C. Clarke: "Any sufficiently extreme emotion is indistinguishable from psychosis."
FYI, the diagrams you linked seem to be doing that .svg thing where most of the important info blends into the background of the page, at least on mobile.
Blurg, thanks.
Nice post!
I didn’t see you mention ‘encephalopathy’ which, for me, is a synonym for brain failure
Thanks! I think of delirium and encephalopathy as interchangeable, and did not want to introduce more terms.