The fifth in a series of blogs presenting a philosophical analysis of the modern mental health system.

In this blog I want to come back to the work of Thomas Szasz. The last two blogs argue that bodily states and processes need to be understood in a different way from the way we understand what human beings think and do. Mental ‘illness’ consists of things that people say and do. For Szasz, an ‘illness’ means a condition of the body, and hence mental illness is not an illness.

According to Szasz, the term ‘disease’ (in its proper and coherent use) refers to changes in bodily structures or mechanisms that produce unwanted physical sensations and experiences, otherwise known as ‘symptoms.’ ‘Illness,’ on this account, is the subjective experience that arises as a consequence of the presence of disease in the body.

On this view, a disease, in its core sense, is a property of the biological system known as the body. Hence, diseases can be described in material terms, and can be understood according to general biological principles that are independent of the individuals they affect. Diseases unfold in more or less predictable ways according to their biological nature. Cancer cells multiple and disseminate, eventually impinging on other cells to such an extent that the organs cease to function. Narrowing of the arteries supplying the heart leads to angina and heart attacks, known as coronary heart disease. It may be possible to influence the course of a disease by modifying one’s body and its environment, such as stopping smoking or getting treatment, but you cannot simply wish a disease away (or so it is generally believed). Biological systems, like chemical and subatomic reactions, are governed by predictable regularities that have nothing to do with the desires and purposes of human beings.

Little attention has been paid to the question of whether or not a disease is necessarily a bodily condition. This seems to be because philosophers of biology or disease who are not principally concerned with mental disorder just assume it to be the case, whereas those that focus on mental disorder usually ignore the issue. The French philosopher of biology, Georges Canguilhem, for example, states that “one can speak with reason of ‘Greek Medicine’ only from the Hippocratic period onward—that is to say from the moment when diseases came to be treated as bodily disorders.”

Many thinkers who are concerned to encompass the realm of mental disorders within medicine implicitly suggest that the terms ‘illness’ and ‘disease’ do not need to refer to the body. They argue that what is essential to these concepts is the fact that they represent disvalued or unwanted states. Peter Sedgewick, for example, points out that there are no diseases in nature. Beyond their ability to cause pain and death, the consequences of physical conditions depend on social expectations and demands. Mild arthritis in the hands may be highly problematic to a violinist, but irrelevant to most of the rest of us. Industrialised societies organised around the productivity of wage labour heighten the impact of chronic conditions that reduce performance, which may be better tolerated in rural societies with more communal traditions.

Sedgewick is right to point out that whether the body functions adequately depends on its environment and the demands it has to meet, and these demands in turn depend on the conventions and expectations of a given society. Simply being a feature of the body is not enough to qualify something as a disease. There is also a value judgement involved about the consequences of that condition and the benefits of treating it, which will differ from one context to another.

But Sedgewick and others take the argument a step further and suggest that it is the disvalued nature of disease that is central to the concept, and therefore that other situations involving a negative value judgement can also be called a disease or illness. This is tantamount to saying that any unwanted situation can be considered to be a disease.

In response to this value-based definition of disease and illness, some thinkers have tried to reinstate objective criteria that can encompass mental disorders alongside bodily conditions. Arguing that physical or biological mechanisms and ‘psychological mechanisms’ can be thought of as equivalent, they extend the concept of illness to include situations, such as those we refer to as ‘mental disorders,’ that are defined by the presence of unwanted behaviours. Hence psychiatrist Robert Kendell argues that “the differences between mental and physical illnesses, striking though some of them are, are quantitative rather than qualitative, differences of emphasis rather than fundamental differences.”

Jerome Wakefield’s much-discussed concept of ‘harmful dysfunction’ is an example of this thinking. Wakefield elides bodily dysfunction and psychological dysfunction by claiming that both are objective situations that can be defined by a failure to fulfill evolutionary purposes. However, just as the fact that cancer and crime are both negatively valued situations does not render them the same kind of thing, the idea that mental and physical mechanisms might both be evolved also does not confirm their equivalence. Our ability to be flexible and adaptable, in other words our free will, can be seen as an evolved phenomenon, but this doesn’t make human behaviour the same sort of thing as the structure of the eye or the dexterity of our hands.

Moreover, Wakefield’s reliance on evolutionary theory adds no value to the understanding of physical diseases, let alone the definition of mental disorder. Medicine uses mechanistic not adaptive explanations of function. We define the normal function of the heart, for example, as the level of functioning required to keep the rest of the body alive and well. There is no need to postulate natural selection or an evolutionary teleology. Indeed, evolutionary psychology has been the subject of extensive criticism, and its claims to objectivity have long been recognised as spurious. It is shot through with evaluative judgments about what ‘normal,’ ‘natural’ or ‘proper’ mental functions and behaviour consist of.

By equating psychological and biological dysfunction Wakefield is ultimately suggesting, like Sedgewick, that there is no value in the distinction between an unwanted condition of the body and other problematic situations. Yet this is surely not true. It is evident that in real life we find it important to distinguish situations that arise as a consequence of a bodily state or event, and those that are manifestations of what we recognise as human behaviour; that is, activity initiated by an autonomous, self-directing individual. Consider the importance of distinguishing ‘real’ epileptic fits from ‘pseudo-seizures’, for example! We treat people who ‘fake’ fits, consciously or unconsciously, differently from people whose fits originate from abnormal electrical impulses in the brain.

Working in a drug detoxification unit this is a real, everyday problem. People who have been using large amounts of alcohol or benzodiazepines are liable to have epileptic fits during detoxification, which can be dangerous and life-threatening and need immediate treatment with benzodiazepines or other anti-epileptic agents. People with a history of addiction may also fake fits in order to obtain these substances, however. If you give people who fake fits anti-epileptic drugs, you not only expose them to unnecessary harm, you also undermine the ethos of the recovery programme for everyone in the unit.

We make an effort to distinguish these different situations because they call for a completely different understanding and response. Making the distinction matters.

Szasz did not deny, as is sometimes implied, that the concepts of disease and illness are what is referred to as normative — that is, they incorporate value judgements about what is ‘normal’. He merely observed that wanted or unwanted, bodily conditions can be described in material, biological terms: “although the desirability of physical health, as such, is an ethical norm, what health is can be stated in anatomical and physiological terms.” If you loosen the association between the concepts of illness and disease and the body, you empty them of their distinctive meaning. They are no longer able to pick out a particular category of unwanted situations and become synonymous with generic terms like ‘problem’ or ‘difficulty’. Divorced from the body, the words cease to have any discriminative power. They become meaningless.

In the next blog I shall address the idea that mental disorders are, in fact, diseases of the body — in particular that they are brain diseases.