Illness, Authority, and the Burden of Proof

Psychiatry is beset by a chronic controversy around the world “illness”. Critics and opponents of the specialty have long been engaged in what the philosopher Ian Hacking called an “unveiling” project, questioning the authority of psychiatrists to label people as ill. This has generally worked by highlighting the lack of an unambiguous marker or validator to confirm the presence of illness. Arch critic Thomas Szasz noted the lack of a physical lesion to prove the existence of pathology, and declared mental illness a “myth”. In a famous early 1970s experiment, Rosenhan and colleagues demonstrated that a single malingered psychiatric symptom could, without confirmatory tests, lead to hospitalization.

Herein lay the unveiling Hacking describes; revealing that something supposedly real was in fact constructed. The broad narrative of these critics was that “psychiatric illness” was a term applied to behaviours and experiences that were not pathological. Unlike other medical specialists, who are experts in demonstrably physical disease process, psychiatrists lack an externally validating terrain. They thus lack the authority to say of their patients “this person is ill”.

Notice the form of the argument; without validating evidence that a physically demonstrable disease process is present, we ought not to use the word “illness”. Thus, in psychiatry, we seem to treat illness as being similar to criminal guilt. A person is healthy until proven otherwise; sane until proven insane. Maybe this is the right way for psychiatry to be organized. We all naturally seek to be recognized as autonomous, reasonable individuals, capable of deciding for ourselves. We recoil from the possibility that our vision of reality may be compromised. Putting the burden of proof on the psychiatrist protects us pre-emptively from the possibility our autonomy is compromised and our slant on the world is “off.”

But it is worth contrasting this state of affairs with other forms of medical complaint. In a recent book about psychosomatic illness, neurologist Suzanne O Sullivan reports on a series of patients with serious physical symptoms. In each case, she concludes the most important causal factor lies in emotional conflict or disavowed stress. Although she does not deny these patients are ill, she does deny that the illness is straightforwardly physical in the way they believe. It is interesting to observe that, contrary to the situation faced by many psychiatrists, Sullivan has to work hard to persuade her patients that they don't have a disease.

Here the burden of proof is somehow reversed. The patients approach the doctor claiming to have a physical disease. Only a complex diagnostic process is able to rule out its presence and allow the symptoms to be accounted for as “psychosomatic”. Even then, there is no disease, but the patient is still ill. How can this be? Doesn’t Sullivan lack the same medical authority as psychiatrists in these instances? Isn’t she, like them, forced to conclude that absence of a disease process entails absence of an illness?

Apparently Sullivan cannot observe her patients’ situations and fail to conclude that they are ill. This seems partly to be sympathetic, and partly intuitive. Sympathetic because Sullivan is clearly at pains to communicate to her patients that she takes their experiences seriously. They feel themselves to be ill. Intuitive because and to all intents and purposes, these patients simply seem to be ill. When an individual is unable to walk, or is subject to persistent and debilitating seizures, we readily concur that we are in the terrain of medicine. We havestrong intuitions about where illness is and where it is not present. How otherwise how could the arguments about disorders like ME/CFS could, get so heated and confused?

Somehow our intuitions about physical and psychiatric debilitation are different. We question psychiatrists’ authority to label their patients “ill” in way we don’t bother to with for other specialties. This is not just a question of objective markers, it is written into how we interpret different experiences. This may amount to a systematic bias against seeing illness in the psychiatric realm. Insofar as psychiatry can suffer from “mission creep” (into the medical-labelling of political dissenters for example) this bias may have its uses. However, despite a relatively vocal movement for the demedicalisation of mental health services, there is reason to suppose that a complete movement away from an “illness model” will not serve everyone.

“Illness” is not only a word imposed top down on people’s subjectivity by patrician doctors, it is also a way of giving form to experiences that are painful, disorienting, dangerous or overwhelming. The idea of experience as illness can make sense of it no less than a narrative about its social, traumatic or affective origins, and is in any case not necessarily in conflict with such a narrative.

It is worth wondering then, why we light so easily on the idea of illness in the case of some forms of overwhelm, and so reluctantly in the case of others. In either direction we run the risk of going wrong. We might reasonably ask who has the authority to say that someone else is ill, but we might also wonder who has the authority to decide who is not.

What's our problem with genetics?

In the field of mental health there is a distinct allergy to the question of genetic influences on cognition. At its most extreme, this allergy leads to a sort of anaphylactic reaction that has been called genetic denialism. A recent example of this (an example that prompted the epithet) is Oliver James’ book “Not in Your Genes”. However, a milder form of the allergy exists, and I call it genetic disavowalism. Genetic disavowalism is far more pervasive than genetic denialism, and finds its way into clinical psychological writing. 

Genetic Denialism has changed little in 30 years

Genetic disavowalism has valid historical roots. There are good reasons for horror when we examine the way that genetic theories have been distorted to promote policies of eugenics and even mass extermination. But as with other allergies, the responses that are mobilized against “gene talk” are out of proportion to the current level of threat. It is misguided to conclude that it is somehow desirable to steer clear of genetics, or “genetic explanations” altogether, or that the field as a whole is tainted by Nazism. As is the case with other allergies, these responses may be counterproductive, or even damaging.

When I talk about disavowalism, I am not referring to certain widely agreed upon facts about the limits of genetics in psychiatry. That is, I am not calling into question the idea that genes are only one part of the aetiological process giving rise to various mental health problems. I am not contesting that the heritability quotient is a limited form of information about the role genetic influences and leaves (for the time being) a “heritability gap” between rates of within-family concordance and accounted variance in molecular approaches to genetics. Neither am I questioning the limited practical application of genetics in many areas of psychiatry. What falls under the scope of genetic disavowalism- what I take to be intellectually unhealthy- is a detectable aversion to even considering psychiatric genetics as a reasonable field of enquiry for aetiology or therapeutics.

Genetic disavowalism can be associated with its own wrongs. I lose count of the number of times I have seen a psychologist descry genetic explanations on the grounds that they imply a person is “permanently flawed” or similar. Flawed? Let’s follow the reasoning. If a genetic explanation implies that someone is permanently flawed then presumably a theory which allows for a more transitory kind of experience (an environmentally determined, understandable “reaction”) only implies that they are temporarily flawed. The time frame changes, but the “flaw” remains. 

This is not a problem with genetics; it’s a problem with how some people (including apparently, critics of genetics) think about other people. The use of the word “flawed” is suggestive of a value judgment that has nothing to do with causes, and everything to do with how you regard a behavior or trait. If you come to the aetiological debate with the view that people with mental health problems are “flawed”, then your inclination to disavow genetics may be a defence against your own internal prejudice.

It can be helpful, in the face of genetic disavowalism, to probe intuitions about the morality of psychiatric genetic research and intervention. If genetic psychiatric research is inherently negatively morally valenced (or if it amounts to a “tedious obsession” as I have seen it said), we might ask whether it should be discontinued.

Here is a case study that bears on the question. In Steve Silberman’s Neurotribes, there is a wonderful description of the origins of our genetic understanding of Phenylketonuria (or PKU), a disorder which can result in profound cognitive and intellectual disabilities. The Norwegian researcher Ivar Følling had noticed a strong smell in the urine of a child who had developed intellectual disabilities. Further testing revealed this to be the result of high phenylpyruvic acid levels, indicative of a difficulty metabolising phenylalanine. Phenylalanine build up in the brain is what leads to the pervasive cognitive difficulties often seen in PKU. Følling showed that the underlying metabolic problem was determined by an inherited abnormality on a specific gene.

This was a serendipitous discovery that came out of a line of investigation that can easily seem hopeless; the search for genes for generalized cognitive disability. Nonetheless, its implications are extraordinary. Children with the gene can now be identified at birth and, with a simple dietary regimen, be prevented from developing the sort of pervasive cognitive difficulties that can make it impossible to live independently. Was this unexpected discovery a bad thing? Are we worryingly closes to a program of eugenics for knowing that there is a form of cognitive disability that is caused entirely by an inherited abnormality on the PAH gene? Is it morally wrong to stave off that disability by resorting to a preventative diet?

The story of PKU will not easily generalize to all areas of mental health, but it is foolish (and a form of ahistorical thinking) to suppose that unexpected shifts in our knowledge about the genetics of mental health can not now lead to other breakthroughs in treatment. In 2016, do we know all there is to know? Psychiatric genetics has been parodied by analogies to a “gene for homelessness or debt”, with the implication that it is conceptually wrong-headed to conduct genetic research in the domains of schizophrenia or depression. Maybe a gene for homelessness or schizophrenia will never be found, but genes or genetic mutations for some specific subtypes of cognitive problems are not out of the question. How to approach genetic research most fruitfully is one issue. Whether that research should take place at all is another one entirely.

Is mental illness denialism a death sentence?

A decision by Pakistan’s highest court, to define schizophrenia as “not a mental disorder” has caused some consternation for legal advocates and psychiatrists. As a result of this ruling, Imdad Ali, a 50 year old Pakistani man can now be executed for a crime he committed in 2001. Ali has a diagnosis of schizophrenia, which his lawyers hoped would mean that (although he has been convicted) he could not be executed as punishment. This hope seems to have been grounded in the fact that Pakistan is signatory to a UN agreement, that individuals like Ali will not be executed if they are “not capable of understanding the crime and the punishment”.

Psychiatrist Joe Pierre has argued that antipsychiatric thinking may play a role in this case. It certainly seems that way superficially. Here’s his reasoning:

1. Imdad Ali is going to be executed because the court has cast doubt on the reality of schizophrenia
2. Mental illness denialism casts doubt on the reality of schizophrenia
3. Mental illness denialism may have fed into this judgment, and may lead to similar results elsewhere.

I think there might be grounds for placing more distance than this between mental illness denialism (something I have pushed back against) and the Pakistani court’s decision. Although the court does seem to make an outrageous ruling (its judgment explicitly states that schizophrenia is not a mental disorder, as defined by the country’s own 2001 mental health ordinance), the grounds for that decision may be closer to the mainstream of psychiatric thought than journalists are accepting. This is a judgement that (despite headlines) seems to have to do not with schizophrenia’s existence, but rather with its periodicity. It’s true (and widely accepted) to say that schizophrenia is not a condition which always effects you in the same way at different times. People with the diagnosis of schizophrenia have a waxing and waning in their degree of mental capacity.

Pierre mentions the insanity defense twice, but that does not appear to be relevant to this case. Ali has already been found guilty, which presupposes that he was a) declared fit to stand trial, and b) not considered “insane” at the time of the crime. There is no incompatibility here. In schizophrenia, the psychosis and disorientation come and go. We think nothing of keeping separate the insanity defense, competency to stand trial and diagnosis per se. Thus, it is possible (under US law at least) to have schizophrenia, be declared fit to stand trial and be found guilty of the crime, provided you were mentally competent at the relevant stages.

This case seems to hinge on whether Ali is competent to be executed. It is a repugnant question. If, like me, you abhor the death penalty it doesn’t seem coherent to imagine people could be competent in the relevant way. Nonetheless, it is a well-established legal framework in the US. It has been unconstitutional since 1986 to execute an "insane" prisoner, which means someone has to decide whether an individual remains "insane" at the time of sentencing. The key detail is that the evaluation of competency to be executed is a decision distinct from the simple presence of a mental disorder. 

This idea is apparently what is being explored now in Pakistan. Here is what the judges seemed to have decided (from what is admittedly a fairly obscure judgement): schizophrenia shows a fluctuating course, therefore it is not a permanent mental disability, therefore it does not fit Pakistan's 2001 mental health ordinance definition of mental disorder; therefore Ali is competent to be executed. This chain of inference doesn’t seem right to me, and yet it is not that far from how things work in many US states. If Ali were on an American death row there would be no question about the legal status of his schizophrenia, but his competence to be executed would be an open question. You can make part of your living as a forensic psychologist, at least in certain US states by conducting assessments that bear upon this question. Entire books are written on the topic.

Pierre has a question in his subtitle: “could mental illness denialism result in the same thing happening in the U.S.?” Before we become concerned about mental illness denialism (an undoubted problem), we might wonder whether the court in Pakistan, rather than denying the reality of schizophrenia (it says explicitly in it judgment that it isn't) is clumsily contesting its nature. Then, rather than worry about this thinking spreading to the US, we should glumly acknowledged that the situation here is not much better.

A strange sad walk though asylum history

It is late afternoon on a warm fall day. New England is quiet and crisp under a pale blue sky and waning orange light. I am alone in a clearing, surrounded by radiant autumn leaves and the cold uniform stones of a cemetery.

In the heart of rural Connecticut, just under a kilometre from a river that wends through the state down to the Long Island Sound, is the graveyard for residents of what was once the state asylum. It is a lonely place, set back from a tarmacked road so that you have to drive along a wide gravel path with the dust kicking up behind you.

The cemetery sits in the lee of a valley with the huge crumbling redbrick buildings of a 19th century hospital just up the hill. Many of those are still in operation but now constitute a network of modern mental health services; inpatient units, community outreach teams and assorted therapeutic services. Although only a stone's throw away, they seem a million miles from this quiet corner. 

An air of calm prevails, with nothing but birdsong and the rustle of dry leaves to break the silence; a quiet that has a grim resonance to it. Although cemeteries are usually places of memory and melancholy reflection this is a peculiarly sad memorial. Other such places I have visited in America are brimming with the stories of the people they house. Whole patches of Queens are devoted to huge granite slabs bearing Irish or Italian names. Walking through them one is struck by the vigour of transatlantic migration, the keenness of struggle, and the strength of kin. 

These stones have no names, instead each is inscribed with a number. A simple designation made by the state hospital at a time when the people who died in such institutions were overwhelmingly anonymous and alone. At first glance it appears a relatively small plot of land, but look at the slabs and you see them creeping up to mark the resting places of over 1600 people. 

It is almost unbearable to think about the individual chains of events that must have led to so many forgotten people being buried here. At a time when all varieties of psychological and physical suffering were grouped into a morass of stigmatized hopelessness, individual stories were routinely submerged beneath an ocean of pessimism and neglect. 

I find myself hoping that at least each burial was attended by a ceremony of some sort, that the staff on the wards had fond memories of the people they were saying goodbye to. At a conference earlier this year I saw historians of madness discuss the turn toward investigating their subject from the perspective of the patients. The anonymity of this secluded graveyard feels like a vivid testament to the need for that scholarship.

Happily there has been an injection of much needed attention here. Between 2001 and 2015, a coalition of people, including retired pastors and the Connecticut Alliance for the Mentally Ill, have overseen the construction of a separate memorial linking the numbers on each of those headstones to the names of those buried beneath. Now three larger slabs stand at the front of the cemetery, with a dignified reminder of the fact that so many humans are buried here. 

Two news articles covered the process of creating the new memorial. This long piece in the New York Times came out just months after the attacks on the World Trade Center, and compared the sheer quantity of numbered dead with the losses experienced in that disaster. This article in the local Hartford Courant marked the successful completion of the project. Both contain moving stories about families finally filling in the gaps in the stories of lost relatives. Multiply them by 1,686 and you can acquire some sense of the human scale.

How could it happen? What made it seem like an anonymous resting place was dignity enough for the people of this graveyard? The Times piece quotes the hospital's chief executive as saying "The reason the patients' names are not on the stones is not to protect their confidentiality, but so it wouldn't bring shame on their families", but that is only partly explanatory. Why was it possible for shame to outweigh the basic human expedient of recognition in death? The question produces a vertiginous feeling. How obvious it seems now that serried ranks of numbered headstones resembles more closely an anonymous mass grave than a respectful final resting place. Which of our current institutional practices will one day look so patently wrong?

What do you mean "invalid"?

Here is a common statement made in debates about psychiatric diagnosis:

"[psychiatric disorder x] is an invalid construct"

This "validity critique" of psychiatric diagnosis arose after the technical overhaul of DSM-III, when the psychometric properties of such classifications became a powerful way of understanding their flaws. Originally, it came from seminal work by Richard Bentall and Mary Boyle, both of whom queried the construct validity and predictive validity of DSM-defined schizophrenia. This was an original and useful way to raise problems with schizophrenia-talk, and it has happily found its way into the mainstream of psychiatric discourse. Unfortunately these contributions get kind of watered down in the endless repetition of a "invalid construct" claim as quoted above. What gets left behind is the veneer of apparent truth, without any substantive meaning.

To say "valid" or "invalid" is not very helpful in itself. Those are words that have both a specific technical psychological meaning and a broader lay meaning. Validity in psychometrics is a term used to describe the extent to which a test or checklist measures something that is actually there or successfully predicts some other event. To understand what is meant by "valid" (or "invalid") we need to ask valid in relation to what? Thus a given questionnaire could be an invalid predictor of suicide, but still be a valid indicator of severely depressed mood.

Psychometric validity is difficult to nail down in the realm of diagnosis because it is not clear what might count as a validating criterion. Bentall and Boyle point out several facts about the diagnosis of schizophrenia, including the fact that symptoms do not cluster together and that functional outcome is not uniform. Those are good things to know, and they undermined pervasive myths about the schizophrenia diagnosis.

But in the broader, lay sense of the terns, it is all but impossible to meaningfully say whether diagnosis [x] is really "valid" or "invalid". What, after all, do those words really mean in this context? The dictionary definition simply suggests "grounded in fact", or "reasonable or cogent". On this definition, surely it is valid to say "I feel ill" (if your first person subjective experience tells you as much), or "I have schizophrenia" (if the technical language using community agrees as such).  If I have a set of experiences that feel subjectively like illness, cause me to meet DSM-criteria for a disorder and that DSM-diagnosis provides a constructive narrative for helping me to live the sort of life I want for myself, is it still an "invalid" diagnosis? In the technical sense of "invalid", it is arguable. In the broader lay sense of "invalid" it seems the answer is a resounding no!

Another way that psychologists increasingly talk of validation is in terms of recognizing the reality of people's experiences. Thus we validate people's sadness or anger by joining with their perspective and agreeing that anger or sadness was a reasonable thing to feel under the circumstances. Failure to do this is called "invalidating", meaning that it seems to undermine the reasonableness of an emotion. Invalidate someone's emotions and you show them they are wrong to have felt them. Invalidate someone's experience of reality and you hint to them that they are crazy.

Talk of lack-of-validity has been a valuable addition to understanding psychiatric diagnosis. But when it gets isolated from its underpinning arguments, validity talk in this context can be invalidating.

(Ab)normal psychology

In a presidential blogpost at the BPS last month, Peter Kinderman reiterated an argument from his book that there is no such thing as abnormal psychology. I have spoken to this debate once before, when I reviewed his book on this blog. Here is what I said then:

A superficially appealing argument raised here is that "abnormal psychology" is an unreasonable field of study; after all, we don't speak of "abnormal physics". There is an important idea here with which I find myself aligned. Using the word "abnormal" is indeed a needlessly unpleasant way of speaking about people, but the physics analogy doesn't fly. All physical phenomena are subject to the same basic laws (as far as we know), but that hasn't prevented the fruitful subdivision of their study into solid state physics, condensed matter physics, and so forth. When people have experiences of psychological distress, these tend to manifest in a propensity toward particular states of mind. Is it really so unreasonable to study these states in their specificity, cautiously categorising them until some better framework is offered?

I still stand by that more or less, but when I re-read Kinderman's argument this time around I felt more disposed to agree with something in the point he makes. What is he driving at here? It's a fun idea to probe.

Psychiatric diagnoses like schizophrenia can be said to be hypothetical constructs. That is to say they are theories about the nature of entities (what type of entities is controversial) that are held to exist. Because it is still hard to find solid external criteria by which to independently validate their existence, they are sometimes said to fail as valid constructs. This is not a fringe argument. It is acknowledged far and wide within academic psychiatry. That is why the validity/utility debate has such traction within the discipline. I have pointed out before that psychiatric diagnoses survive because they come to act as a sort of stand in term for quite real seeming experiences. Where they aspire (and fail) as hypothetical constructs, they succeed as intervening variables.

What does that mean? In the 1948 paper that introduced and distinguished intervening variables and hypothetical constructs, the former are simply a convenient shorthand for some collection of already observed (but potentially unexplained) empirical facts. The latter are supposed to be things, that have some "explanatory surplus"; if you can propose a successful hypothetical construct, you will be able to make new (and accurate) predictions about reality.

That term explanatory surplus is key. Although there is a way of reading Kinderman's argument that is unfavourable to him (namely that one can of course plausibly divide the study of psychology into common and and relatively uncommon processes), he is certainly on to something. Here are two reasons why:

1. In any given case in which an individual has a psychiatric diagnosis, I can make some rough empirical predictions based on aggregated statistical facts about that diagnosis. But because knowledge about psychiatric entities is generally obscured by how poorly defined they are (for now), I am largely at a loss to make tightly-specified predictions about individuals based on a decent theory. "Abnormal psychology" is a collection of useful observations about how certain people behave and what processes are present in particular groups. 

2. Even if I did have a well specified set of facts about such and such a psychiatric entity, the majority of any given person's behaviour will still be best explained by facts that are common to all people. Thus I can usually understand instances of aggression in terms of things like a person's likely fears and wishes, combined with the situational context they found themselves in. I can then add on some nice sounding post-hockery to the effect that they have "poor impulse control" (a variation on a capacity we all have more or less of) or something similar. In the absence of a well set out aetiological theory of any disorder (giving it "explanatory surplus"), I don't really have an explanation yet. Most people's behaviour (even psychiatric patients) can be mainly explained by principles that have been derived from general psychology. Only a little is added by factoring in the useful observations of psychopathogical research. 

I have to be careful. I am not downplaying the value of clinical psychological research. Nor am I one of those people who wants to deny that there could be something like illness processes present in many cases of DSM diagnosis. I think it is unambiguously clear that abnormal psychology exists in the context of neuropsychology and neurology. But I suppose I agree with Kinderman insofar as I think that most of the behaviour of most people can (and should, as far as possible) be understood in terms of the things that are common to everyone.

Delusions and Verisimilitude

What's the one thing everyone knows about delusions? That they're false beliefs. Not so fast. Already we have two problems. First, there is much debate among philosophers about whether they are really beliefs (recently the linguist Dariusz Galasinski has written a fascinating post about whether delusional utterances even always have to be propositional statements).

Additionally, it's not clear that delusions always have to be false. An oft repeated sentiment in psychiatry is that even a true belief ("my wife is cheating on me") could be delusional if held with the right (or, I suppose, wrong) sort of conviction. That idea is usually attributed to Karl Jaspers, but not having read him yet I can't confirm. I have also seen it attributed to Lacan, but I don't recall coming across it when I read his weird, poetic Seminar on the Psychoses. Perhaps someone could point me to the source.

I am intrigued by the possibility that a true statement could be a delusion. It seems superficially rather a contradiction in terms, after all "delusional" is a rhetorical way of describing something as patently false. Nonetheless it makes some sense. It seems possible to have a pathological conviction about something true. Imagine correctly insisting that it was raining outside when you had no means of knowing it were so. Healthy assertion about most things contains withing itself the germ of the possibility that the person asserting could be wrong.

It seems then that we can be delusionally correct in certain circumstances. Is there also another way delusions could be true? Could they be, as I think some therapists would like to suggest, a form of communication about reality? Could it be that delusions, even quite wild ones ("I am having my mind read by the president"), have some element of truth to them?

Some people think so. For example, one therapeutic approach suggests finding the relate-able component of any delusional utterance and focusing on that. A supervisor recently told me that she was once confronted by a patient yelling "we're at war!" and responded by saying "you must be very frightened". I can't resist the detail that the patient turned out to be flatly correct (it was 2003 and she was referring to the outbreak of the Iraq war), but my supervisor's approach was a good one I think. When someone says something to you that is on-the-face-of-it at odds with your understanding of reality, it seems more communicatively cooperative to find the part that both of you make sense of. "You think other people can read your mind? Well that must feel terrifying and very exposing."

Such an approach sometimes gets packaged up as a form of relativism or pluralism, the idea being that there is no such thing as one truth. That might feel quite comfortable for people of a certain philosophical persuasion; if you are a pluralist or post-modernist about truth, then you needn't be troubled by the idea that any given statement is false.

Do we have to have different truths?

Unfortunately I like the therapeutic stance but not the philosophical posture. I have come to belief in truth. By this I just mean that I think that some states of affairs are the case, while others are not. What is more, I think most people secretly agree. If you jump off a bridge (all other things being equal), you'll end up moving downwards. If there were nothing that were true it would be supremely weird that we managed as a species to agree over so many things.

So what do we do? Can we still say, following sympathetic therapists, that delusions have some truth to them? I think we can. Beyond the idea that some statements are true and others false, there is the idea in philosophy of science, that any given statement can be more or less true; that is, have more or less verisimilitude. Take these two statements: 1. "There is no such thing as schizophrenia" 2. "Schizophrenia is a real illness". They seem mutually contradictory, as though they couldn't both be true. They certainly cause a lot of argument. Regular readers of this blog might already have a view about which is right and which is wrong.

I think such arguments usually arise because the people apt to make one of those statements often think they are saying something that could be simply true or false. This is a mistake. One of the reasons such contradictory statements can exist (and it is surely one of the reasons that relativism about truth is such a respectable position in some circles) is that so many of the claims made in this domain are impossibly under-specified as truth-assertions. That is to say, my example statements 1 and 2 use such loosely understood words ("schizophrenia", "real") that we cannot gauge their truth value without interrogating some hypothetical speaker to get further qualification.  For what it's worth I think both statements have some verisimilitude. I go back and forth about which one I think has more truth than the other, but they are both getting at something basically correct.

How does all this help us with delusions? Delusions are like the statements studied by philosophers of science. They are often (though not always) statements about how the world is. If this were not so we might not bother calling them delusions to begin with. People falsely claim they are being watched; that they are of unusually superior ability; that they are infected with some fatal disease. It seems right to be aware that such beliefs are are often untrue. At least the headline assertion is often false. However delusions are usually complex and under-specified statements. Minimally, a person who makes an outlandish claim about the world is also making a less ridiculous one about what it is like to be them at that moment. Broadening our view somewhat, they might be making a quasi metaphorical statement about some aspect of their environment. I will not be saying anything radically new if I suggest that sometimes, delusions are informative in surprising ways.

Therapeutically this is nothing new. Sympathetic listeners have long held that delusions contain something true. Confronted with an uncomfortable contradiction between a patient's beliefs and their own, many people's instinct seems to be to assert the possibility of a plurality of truths. People of some philosophical persuasions (self included) find this too wishy-washy. Perhaps verisimilitude can help us square the circle.