Tuesday, November 12, 2013

Are mental illnesses real? (Part One)

It may be a push, but I think it is fair to say that no branch of modern medicine faces the same existential challenges as psychiatry. To give a sense of the problem, a quick browse through Amazon reveals a plethora of books, many published within the past ten years, that either directly challenge the legitimacy of mental illness, call into question the medicalisation of the mind, or dispute the unholy alliance between “pharma” and psychiatry. This is to say nothing of the organisations and religious groups (most famously the scientologists) who critique modern psychiatry and try to dismantle its apparatuses.

None of this to suggest that other areas of medicine are free from existential challenge. Far from it. There are plenty of AIDs and cancer denialists out there too, and their critiques often follow a similar pattern. Nevertheless, I would submit that those forms of denialism are more obviously “fringe”, and their arguments more easily refuted, than those which relate to psychiatry and mental illness.

Part of the reason for this is philosophical. The attempt to identify, diagnose and treat mental illness seems to bring the mind within the scope of biomedical science: to “reduce” mental phenomena to scientifically tractable, manipulable and treatable “disorders”. This cuts to the core of one of the central projects in modern philosophy: the reconciliation project. This project tries to determine the appropriate relationship between the world as it seems to be to us (the manifest image) and the world as it seems to be when viewed through the lens of modern science (the scientific image).

As such, the topic of mental illness — what it is and how it should be treated — is one that is particularly ripe for philosophical analysis and debate. The purpose of this series of posts is to look at some aspects of this analysis and debate. Specifically, to look at various attempts to determine what an “illness” or “disease” really is, and at arguments for or against the legitimacy of “mental illness”. In the process, we’ll take in some of the key contributions to the literature, from Thomas Szasz’s infamous “mental illness is a myth”-argument, to Jerome Wakefield’s “harmful dysfunction” analysis of mental disorders. As ever, much of the discussion will be shaped by my reading of a particular book or article, in this case Tim Thornton’s Essential Philosophy of Psychiatry. I shall, however, feel free to deviate from, expand upon, or critique Thornton’s work at several points.

In the remainder of this post, I’ll start the ball rolling by looking at some arguments from Thomas Szasz.

1. Szasz and the Myth of Mental Illness
Although anti-psychiatry has a long pedigree, and although exponents of the view can be found in many walks of life, Thomas Szasz’s contribution to this field is particularly noteworthy. Szasz is a trained psychiatrist who, in the 1960s, penned a famous and influential critique of his own profession. Let’s first look at a short video in which he outlines some of his basic positions.

What are we to make of this? The video is short, carefully edited, and the arguments pithy and provocative. It captures in one place, several themes and ideas that Szasz has developed more fully and more carefully elsewhere. Indeed, one thing that is noticeable about Szasz’s work is that it is slightly more nuanced, and slightly less declaratory in its academic presentations than in its public ones.

To take one example of this, Szasz’s discussion of drapetomania and ADHD in the above video is somewhat misleading. Although it is indeed true that drapetomania was a diagnosis at the time of slavery, it is a mistake to presume that it was widely accepted. On the contrary, it was ridiculed in the (US) North at the time. Acceptance seemed to split along political lines. The same does not appear to be true of ADHD.

Still, there is an important point being made here. What counts as a mental illness seems to be at least somewhat dependent on political and cultural factors. Homosexuality, for instance, was once classified as a mental illness in the psychiatric bible — the Diagnostics and Statistical Manual — before eventually being removed in 1980. This seems to have been driven to political and cultural acceptance of homosexuality. We don’t see the same kind of dependency when it comes to TB or polio or cancer. It would be odd for these diseases to be politically constructed. They are supposed to be objective, not culturally relative. Aren’t they? Why should mental illnesses be any different?

It is exactly this point that Szasz tries to make in his work. He tries to argue that there is something deeply wrong with the notion of “mental illness” and with any claim that it can be treated through medical means. We’ll look at three arguments he makes to this effect. The first rejects any attempts to subsume mental illness within the class of brain illnesses; the second casts a suspicious eye over the diagnosis and definition of mental illnesses; and the third, and most important, presents a general account of illness and medical treatment, and tries to show how mental illness falls outside of its scope.

2. Mental Illnesses are not Brain Illnesses
There are such things as brain illnesses. That much is uncontroversial. If I have a tumour in a particular region of my brain, or if I have a virus that affects certain parts of my brain, or if I have a degenerative brain disease like MS or ALS, then I can be rightly and fairly said to have an illness that needs medical care and attention. But if that’s right, then what’s the big deal about mental illness? The mind is a product of the brain. So why can’t all mental illnesses simply be subsumed into the category of brain illnesses?

To state this argument more formally:

  • (1) Brain illnesses are real illnesses.
  • (2) The mind is constituted by the brain.
  • (3) Therefore, all mental illnesses are brain illnesses (from 2).
  • (4) Therefore, mental illnesses are real illnesses.

Is this argument any good? Let’s take it premise-by-premise.

The first premise is problematic in two respects: (i) the nature of the general class of brain illnesses is unclear; and (ii) the sense in which the word “real” is being used is unclear. The former is a problem insofar as the argument may over-rely on obvious cases of brain illness and assume that all cases are as uncontroversial as these. The latter is a problem that plagues this entire debate. For now, we can simply assume that “real” means that there is widespread, intersubjective agreement about when the illness is present or not. But if we accept that, then it’s no longer clear that mental illnesses are “unreal”.

The second premise assumes a strong form of mind-body monism. That will be objectionable to some people. And the thing is, the strong form is needed if the rest of the argument is to work. If you accepted that the mind was dependent on the brain in certain respects, then you might be able to account for some mental illnesses in terms of the brain, but not all.

That said, even if you accepted mind-body monism, there might still be problems. This is where Szasz’s original critique comes into play. He points out that the ability to account for mental illnesses in strictly neurological terms is limited. The relationship between the brain and the mind is a complex on. Even if we accept that mind and body are made of the same stuff, it does not follow that talk of mental illnesses can be reduced to talk of brain illnesses.

Now, Szasz thinks that there is a deeper reason for this: one that links to how mental illnesses are defined and diagnosed. We’ll get to that later. In the meantime, I’d be willing to agree with the gist of his critique. In other words, I would be willing to question the inference from premise (2) to (3). Although we know much more about the mechanics of the brain, and the connection between the mental and neurophysiological, than we did when Szasz penned his original critique, I still agree that we are a long way from replacing mind-talk with brain-talk.

More generally, I would object to the basic strategy underlying this argument. I don’t think we have to analogise mental illness to brain illness in order to determine whether it is real or not. (This is something that will come up several times in this series.)

3. The Reification-Causation Argument
Typically, diseases and illnesses are diagnosed by means of symptoms. The symptoms are externally observable and testable indicators of the underlying disease. For example, a rash with itchy red blotches on the skin is a classic symptom of chicken pox (a viral infection). The illness is the underlying cause of the symptoms. It is by treating these causes that medicine earns its bread.

Szasz’s second argument claims that this relationship between symptom and disease is subverted in the case of mental illnesses. In other words, that a mental illness is simply a descriptive label we apply to a collection of symptoms, not an underlying cause of those symptoms. Take depression as an example. This is diagnosed by means of symptoms: low mood, anxiety, sleep disturbance, poor appetite, loss of energy etc. If you exhibit a sufficient number of these symptoms, you are diagnosed with “depression”. But depression is not the name for an underlying illness or cause of the symptoms — we don’t know what the underlying mechanism is — rather “depression” is a label for those symptoms.

The problem then, as Szasz sees it, is that this label becomes “reified”. That is to say, we are tricked into thinking that the label is itself a “thing” with causal powers. This leads us to believe that it is a illness much like any other; that it is something toward which we can direct our medical interventions. The reality is quite different.

You may well wonder whether this is a significant problem. After all, it sounds like something we do all the time, even in relation to other illnesses, without thereby undermining the legitimacy of research into that descriptively defined category, or the plausibility of crafting medical interventions to address the symptoms.

What might be going on here is that Szasz is trying to highlight the absurdity of treating mental illnesses through medical means, and that he thinks the reification of a descriptive label is one way in which this absurdity manifests itself. If so, his argument is problematic. This becomes clear once we look at his main argument against the legitimacy of mental illness.

4. Szasz’s Central Argument
Szasz’s main argument against the legitimacy of mental illness works from a general account of the nature of disease and medical treatment, and then purports to show that mental illness falls outside the scope of that account.

The starting point is a norm-based account of “illness”. As Szasz sees it, an illness is a deviation from some kind of norm. In the case of medical illnesses properly-so-called, the norms in question are biological and physiological. There is some pathological tissue (e.g. a tumour) or pathogenic organism (e.g. HIV), whose presence disrupts the normal biological structure and functioning of the body. Pathological disturbances of this sort are objectively discernible, and capable of being treated through pharmacological or other medical means.

Medical Illnesses Properly-so-called: X is a medical illness, properly-so-called, if it involves the deviation from a biological or physiological norm of the human body. (The appellation “properly-so-called” is added to indicate that it is properly an object of medical diagnosis and treatment).

The problem is that mental illnesses do not involve normative deviations of this sort. Though we have searched for some underlying mechanism for many mental illnesses, they remain elusive and dimly understood. Indeed, the literature is overflowing with multiple proposed pathological explanations for “illnesses” like schizophrenia, depression and psychopathy. Szasz thinks that the main reason for this is that mental illnesses are primarily defined in terms of social or political norms, not biological/physical ones. In other words, that a person is classed as a “schizophrenic”, “depressive” or “psychopath” because their thoughts and behaviours do not conform with socially acceptable standards. This is why mental illnesses are so politicised: their very essence is determined by reference to politicised norms.

Hence, mental illnesses are not medical illnesses, and it is absurd to treat them as such:

Since medical interventions are designed to remedy only medical problems, it is logically absurd to expect that they will help to solve problems whose very existence have been defined and established on non-medical grounds. 
(Szasz, 1972, p. 17 IDEOLOGY AND INSANITY)

To distill all of this into a formal argument:

  • (5) Medical illnesses (i.e. those properly diagnosed and treated through medical means) involve the deviation from some biological or physiological norm of the human body.
  • (6) Mental illnesses involve deviations from social/political/ethical norms, not biological or physiological ones.
  • (7) It would be absurd to treat deviations from one set of norms with the tools for treating deviations from another set of norms.
  • (8) Therefore, mental illnesses are not medical illnesses and it would be absurd to treat them as if they were.

Once the logic of the argument is exposed in this manner, its flaws become pretty obvious. For starters, it relies on a contentious, and arguably outmoded characterisation of “medical” illness. Apart from its convenience for Szasz’s argument, is there any reason to think that medical illnesses (or, indeed, medical interventions) must be restricted to biological or physiological norms? Not particularly. Even if it was true that medicine has its historical origins in such standards, there is no strong reason to think it must remain restricted to them.

That said, there are difficult issues here relating to the philosophy of categorisation and the boundaries between different disciplines and concepts. We’ll touch on these later in this series, but for now I would simply note that even though many agree that Szasz’s definition of “medical” illness is outmoded, they often do so by way of defending an alternative, biologically-grounded, definition of illness. Thus, biological and physiological norms continue to play a role in the categorisation of mental illness.

That brings me to the second major problem with Szasz’s argument. The implicit assumption underlying both premise (6) and (7) is that mental illnesses are either one thing or the other; that they are either deviations from socio-political norms, or deviations from bio-physiological norms. But why couldn’t they be both? If mind-body dependence of any type is true, then it is quite possible that deviations of the former type could involve deviations of the latter type. Furthermore, if mind-body dependence of any type is true, then it is quite possible that treatments designed to affect the latter type of deviations could be effective against deviations of the former type.

The result of this would seem to be that Szasz’s argument fails. But where does that leave us? Well, with an obvious question: if Szasz’s account of medical illness is flawed, is there a more persuasive alternative? And would mental illnesses be medical illnesses properly-so-called under the terms of that alternative account? These are questions we shall pursue the next day.

1 comment: