Descriptive v. normative accounts of disorders

The status of mental disorder as illness or disease is still a potent source of debate (for a review, see Reference FulfordFulford, 1989; see also Box 2). Much of the debate has centred around the tension between what are called descriptive and normative accounts. Descriptive accounts of disorders claim that it is possible to describe and classify a disease and/or illness without making some sort of value (or normative) judgement about the concept. Normative accounts claim the reverse: that there is no ‘objective’ account of disorders that does not contain some reference to an established value or norm. Theorists such as Boorse (1975) have argued that the term ‘disease’ describes the pathological processes that then give rise to ‘illness’ as experienced by the patient. ‘Diseases’ then are those processes that can be described objectively, whereas ‘illness’ is more subjective, and necessarily involves a normative (value judgement) component.

Biological disadvantage

This distinction between disease and illness has been highly influential, although still leaving room for debate; for example, whether, and to what extent, the terms ‘illness’ and ‘disease’ may actually be synonymous. The arguments become even more complex when applied to mental disorders. Most readers will be familiar with claims that all diagnosis of mental disorder is really ‘only’ or ‘just’ a type of value judgement (an argument put most forcefully by Thomas Szasz). Boorse himself suggested that, on this account, it is difficult for any mental disorder to be a disease, although there might be many mental illnesses. Scadding (1988) argued that there may be different overlapping accounts of diseases (syndromal, pathological or aetiological), but that the key feature of a disease is related to the extent to which it puts a biological organism at ‘biological disadvantage’. This notion of biological disadvantage has been used to justify the claim that mental disorder has equal disease status with physical disorder (e.g. Reference KendellKendell, 1975).

Harmful dysfunction

Wakefield (1992) has argued that it may be helpful to understand mental disorder as ‘harmful dysfunction’: a combination of a normative illness account and a descriptive account of loss of function, as determined by evolution. Other theorists have argued that the evaluative/normative aspect of diagnosis is an essential feature of both physical and mental disorders (e.g. Reference FulfordFulford, 1989; Reference Engelhardt, Lindemann Nelson and Lindemann NelsonEngelhardt, 1999), and mental disorders therefore need not be seen as something conceptually different. The fact that value judgements may be part of diagnosis does not mean that there cannot be agreement between clinicians, or that the disorder is less ‘real’ (Reference Fulford and HeginbothamFulford, 2000).

Negatively evaluated behaviour

Few of these theorists have applied their analysis to personality disorder. Formalised diagnostic criteria, such as the DSM or ICD, have tended to equate symptoms with negatively evaluated behaviours, such as deliberate self-harm or violence to others. This causes conceptual problems because usual accounts of illness, and illness behaviour, define ‘symptoms’ as actions or experiences that are not willed, desired or chosen by the patient. However, negatively evaluated behaviour is so evaluated precisely because it is perceived to be chosen or willed by the patient, and behaviours or experiences that are willed or chosen are not symptoms.

Behaviours and symptoms cannot always be synonymous, especially in the domain of negatively evaluated behaviour. Therefore a theoretical approach that classifies or understands personality disorder in terms of behaviour leads to two problems. Either any negatively evaluated behaviour, such as self-harm or violence to others, is seen as actually willed ‘badness’ (leaving aside for a moment what that might mean), and people with personality disorders are equated with people who behave badly; or it may be argued that ‘bad’ behaviour is not a feature of illness, and therefore people with personality disorder are not ill (e.g. Reference EldergillEldergill, 1999).

There are real philosophical objections, and empirical difficulties, with both positions. One principal objection is that ‘bad’ behaviour can be associated (but is not synonymous) with some types of mental illness, as demonstrated by the risk and mental disorder literature. Another objection is the albeit limited evidence that some aspects of ‘bad’ behaviour have a neurological substrate, and may be influenced by genes for arousal and affect control; whether this would be sufficient to justify the definition of personality disorder as an ‘illness’ is a moot point in itself.

Focusing on negatively evaluated behaviours as symptoms distracts attention from other ways of conceptualising ‘personality disorder’. More recent accounts (including DSM–IV; American Psychiatric Association, 1994) emphasise the significant failure of interpersonal functioning seen in personality disorder, which arises as a result of a variety of psychological deficits (Reference Blackburn, Millon, Simonson and Birket-SmithBlackburn, 1998). Some psychiatrists have argued strongly that personality disorder is an illness on the grounds of resulting biological disadvantage to the individual (Reference GunnGunn, 1992 Reference Gunn, 1999). Other clinicians have noted the degree of subjective suffering experienced by patients with personality disorder (Reference NortonNorton, 1996), which would normally be understood as a necessary (although not sufficient) feature of an illness. Many studies have noted that patients with personality disorder frequently also suffer from other concurrent mental illnesses, such as anxiety, mood disorders and schizophrenia. Taylor (1999) has argued that one can claim personality to be an illness in so far as it reduces individual variance; people with personality disorder are more like each other than not.

The sickness role

A possible solution to the problems described above may lie in Talcott Parsons’ notion of the ‘sickness role’. People who are ill are expected to avoid behaving in ways that exacerbate their condition, accept the idea that they need help, have the desire to get better and seek competent help to do so (Reference MechanicMechanic, 1978). However, many people with personality disorders, although claiming to be ill and in need, do not behave in the ways expected of a sick person. Perhaps we could understand this failure to fulfil sick role expectations as a type of psychological disability – an incapacity to obtain care effectively – which would undoubtedly convey a biological disadvantage in the long term.

Disability

Fulford (1989) has argued that it might be helpful to understand personality disorders as disabilities, rather than illnesses. Accounts of disability usually emphasise the chronic nature of the patient's problems; they also emphasise the interpersonal aspects of function and dysfunction for people with disabilities. Some readers may remember an advertising campaign for people with disabilities that ran the slogan “Our biggest handicap is other people's attitudes”. Such an interpersonal view is found in American legal definitions of disability (Reference Silver, Lindemann Nelson and Lindemann NelsonSilver, 1999) and it may be a useful way to understand the difficulties faced by people with disability in terms of making choices and being agents of their own destiny (Reference AgichAgich, 1993).

Is personality disorder an illness?

The status of personality disorder as an illness therefore remains contentious, especially while it is defined simply in terms of behaviour. Scadding (1988) has argued that most accounts of mental disorder are at a syndromal, or symptom level, and that illness claims are stronger when there is an aetiological account. Aetiological models have only recently been developed for personality disorder. These models draw on research from longitudinal follow-up studies of child development, and the impact of traumatic events of the personality functioning of adults. Both retrospective and longitudinal studies suggest that early childhood adversity is a potent risk factor for the development of a personality disorder in adulthood (Reference Modestin, Oberson and ErniModestin et al, 1998; Reference Johnson, Cohen and BrownJohnson et al, 1999). Studies of the effects of exposure in adulthood to traumatic and frightening events also indicate that such events may cause change and damage to the personality (as found in the diagnosis of ‘enduring personality change after trauma’, defined in ICD–10; World Health Organization, 1992).

If external events in both childhood and adulthood can shape adult personality functioning, then it is possible to understand personality disorder as an acquired, rather than an innate, condition. Although this argument will not deal with all the conceptual difficulties surrounding the disease/illness status of personality disorder, it does at least challenge the view that some people are just ‘born’ with personality disorder – a sort of psychiatric version of St Augustine's notion of original sin.

Seven-factor model of treatability

What makes a physical condition treatable? I would like to suggest that treatability is a function of seven factors operating simultaneously (Box 4). No one factor will determine a condition's treatability and, especially, its ‘untreatability’.

We can apply this model to any disorder. I will take as an example the treatment of cancer, partly because it is a disorder that sometimes attracts fear and stigma as well as sympathy, and partly because the term ‘untreatable’ is a term of significance for cancer patients and their families.

The type of cancer is a crucial factor in looking at treatability and prognosis, since it is well established that different types may be more or less treatable. The treatability of the cancer will depend on its anatomical context (site) and nature (e.g. histological grading, differentiation). The spread of the cancer affects its treatability – more extensive spread may make some types of treatment more difficult. Premorbid health is a relevant factor in assessing treatability, in so far as it reveals risk and resilience factors that may affect the course of the disorder.

The timing of any treatment for cancer influences treatability, given that there is evidence supporting early rather than late intervention. This in turn relates to the process of diagnosis and identification of the problem. In many cases, treatment is delayed, either because symptoms are not understood as being those of cancer, or because symptoms are thought to be caused by another condition. Such uncertainty about identification of symptoms and diagnosis can lead to delay, which in turn affects treatment response.

Once detected, treatability is affected by the availability of specialists familiar with the specific problems posed by different sorts of cancer. There is good evidence, for example, that the treatability (and prognosis) of breast cancer is influenced by the availability of specialist breast cancer surgeons. Such specialists are backed up by specialist teams, with access to specialist facilities and equipment. Such specialist treatment rarely provides a cure for the cancer; nevertheless, therapy is still offered that improves quality of life and offers support to those who care for and support the patient.

Lastly, most cancers are more treatable now than 10 or 15 years ago: better understanding of the different conditions, their course and nature have offered improved ways of offering treatment. Very few cancer treatments, especially for severe conditions, have been exposed to randomised controlled trials to prove their efficacy; yet they are used clinically to good effect. It is also worth considering the strong ethical arguments against carrying out such trials.

Application of the seven-factor model to personality disorder

I hope it will already be apparent that there are parallels between the treatment of cancer and the treatment of personality disorder. In relation to diagnosis, a simple statement of ‘personality disorder’ is likely to be misleading. Most individuals can be diagnosed as having more than one personality disorder, indicating a range of difficulties. The predominant type is relevant, however, because different interventions may be indicated for different types of personality disorder (Reference DavidsonDavidson, 2001). The evidence base for treatment of personality disorder generally is still limited, but this concern is more a feature of Factor 7 (i.e. state of scientific knowledge) than a characteristic of the disorder itself. It is also worth remembering that 20 or 30 years ago, ‘cancer’ was also treated as a somewhat unitary diagnostic identity with a gloomy prognosis.

Disclaimer

Although the facts are clinically accurate, Kieran's case is fictitious and does not represent any real patient, alive or dead. The views expressed here are those of the author alone, and do not represent the views of either Broadmoor Hospital Trust, or Camden & Islington Community Health Services Trust.