MODELS FOR MENTAL DISORDER

FUNDAMENTAL DIFFERENCES BETWEEN THE COGNITIVE-BEHAVIOURAL MODEL AND OTHER MODELS

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Tyrer, Peter J., author.
Models for mental disorder : conceptual models in psychiatry / Peter Tyrer. – Fifth edition.
p. ; cm.
Includes bibliographical references and index.

ISBN 978-1-118-54052-7 (pbk.)
I. Title.
[DNLM: 1. Mental Disorders. 2. Models, Biological. 3. Models, Psychological. WM 140]
RC437.5
616.89–dc23

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PREFACE

A great deal has happened to mental health in the 26 years since the first edition of this book was published. Rather shamefacedly in retrospect, we intended it originally to be a guide for psychiatrists and students in the mental health professions only when we first conceived the book. At that time the people who received mental health care and their relatives had only distant knowledge of how psychiatrists viewed their world. Now everything is different and I would like to think this is for the better. Mental health professionals can no longer hide behind jargon, obfuscation, half-truths and their perceived status in their interactions with others. Their activities are now centre stage and open to scrutiny from their other colleagues, regulatory bodies, patient lobby groups of various sorts, professionals from other disciplines, and the general public. ‘What are you doing, what is the reasoning behind it, and what is the likely outcome?’ are the questions everybody is asking. Of course, this is not only true of mental health professionals but indeed of all medical practitioners in this new spirit of openness. The problem mental health professionals have is they are not singing from the same hymn book; the cacophony of sound emanating from their vocal chords is not harmonious or synchronized. The aim of this book is to explain why, but not to criticise unduly, and instead to attempt a synchronization that makes the mental health choir a joy to listen to.

To do this I have brought up to date each of the four major models of mental disorder and added extra interlocking pieces that make the integrated model a more successful one. Because I understand that many who receive psychiatric services are naturally keen to know more about the reasoning behind their care, the language has been edited slightly to make it more readable and easily understood. But I apologise if I have failed in my task here. For the past 10 years I have been editor of the British Journal of Psychiatry and have tried to improve the readability of the journal while maintaining high scientific standards. The sad fact is that high scientific standards usually go with very turgid reading and I hope that I have been able to overcome this to some extent.

You will note that the pronoun ‘we’ has now become ‘I’ in this fifth edition. I am very sad to report that my fellow author and illustrator, Derek Steinberg, died shortly after the last edition of this book in 2006, but I have retained most of his cartoons as they remain a fitting memory for his talents. Derek was more of an adherent to the psychodynamic model than the others in this book and I do hope in editing this particular chapter I am being fair to his aims and intentions. We had great fun in piecing together the different chapters of this book and throughout this time, despite many arguments, I never once heard Derek raise his voice. This is not easy when negotiating with an irascible academic with strong feelings and in the editing of this fifth edition I have imagined Derek sitting behind me and reminding me that I need to tone down some of my more extreme views. I would like to think that he has succeeded here but that is for the reader to decide.

I should like to thank my editorial colleagues in the Royal College of Psychiatrists, particularly those who had been serving on the Janitor Committee, for helping me to maintain my precarious position on a rickety fence separating the domains of the adherents of each of my four models, when judging papers for publication. They have helped me to agree that all models can win and all can have prizes. I also thank Peter Lee, a model social worker, and my wife, Helen, for helping me to develop the social model much more coherently, and for the development of nidotherapy, which owes a great deal, much more than she may realize, to her. Finally, I must acknowledge the contribution of my twin cats, Running Thunder and Chasing Small, for being secure custodians of my manuscript, and for acting as my flanking cavalry as we move into the jousting arena where the battle of the models will begin.

ACKNOWLEDGEMENTS

This fifth edition has been helped greatly by the discussions I have had with many outside the field of psychiatry. These particularly include my wife, Helen, whose experience in general medicine, general practice and cognitive-behavioural therapy has helped enormously in my understanding of how we are seen by others, and also by colleagues in general medicine where we have recently been involved in many studies in liaison psychiatry. I have also had many stimulating and amusing arguments with Sandra O’Sullivan and Clinical Studies Officers in the North London hub of the Mental Health Research Network that have also altered my views, I hope for the better. When you are involved with trying to persuade patients to take part in research studies in mental health you realize that both they and their carers, including other physicians, have widely disparate views about mental health and the many models that underlie interventions. These have convinced me that models of mental disorder will continue to be constructed, sometimes crazily, often inappropriately, but always with some value, for many years to come, and, despite all their failings, we would be lost without them.

INTRODUCTION

Welcome to models for mental disorder. It may seem an odd subject, but it is not peripheral to understanding of mental illness. Many years ago I was responsible for the undergraduate teaching programme in psychiatry at our medical school. One of our students showed great aptitude in the subject and told me that he would like to specialize in psychiatry after he qualified. I gave him every encouragement, not least as this subject tends to be low on medical student career priorities. I did not think much more about it until I saw him shortly after his final examinations, where he achieved distinction in psychiatry, but also in some other subjects too. He was looking a little discomfited when I saw him and I asked him if anything was the matter. He told me he had just come out from a two-hour meeting with the Dean of the medical school. He added at some length exactly what had happened. ‘I have heard a rumour that you want to specialize in psychiatry,’ said the Dean, ‘this can’t be correct, can it?’ The student said it was. ‘What on earth do you think you are doing?’ said the Dean. ‘Psychiatry is not a proper part of medicine. People tend to go into it if they fail at everything else, but you are an outstanding student who ought to be doing something better.’ ‘I’ve considered all the options, sir,’ said the student, ‘but I feel more comfortable with specializing in mental health than any other part of medicine and I feel I can be of more value there.’ ‘But psychiatry is not a scientific subject,’ expostulated the Dean, ‘it has no proper base. Most of the people practising it rely on their experience and opinion only. Do you really want to specialize in a subject where everyone has different views and it is the loudest voice that wins, not science?’

The conversation went on in this way for some time and what really surprised the student was how much prejudice there seemed to be against the subject of psychiatry. The interview was entirely counter-productive; the student was even more determined to specialize in mental health after it took place and subsequently enjoyed an extremely successful career in the subject, never doubting that this was the right choice of career. But although this account could just be cited as yet another example of stigma and prejudice against mental health, it is also possible to look further and understand why other doctors look at psychiatry askance, and why from a distance it appears to be a subject with no clear philosophy, rhyme or reason. Doctors in general medicine, if asked what model they practise, would probably ask the questioner to repeat the question, as it is not one which they would normally think about. They practise the disease model, the one described in the first chapter in this book, and because they have been taught right from the beginning of their training in this model, they recognize it as the truth rather than a model, as they could not contemplate looking at the subject in any other way. Psychiatry has tried hard to adopt the disease model but despite valiant efforts to make it work, it only covers part of psychiatry. John Bucknill, the founding editor of the journal I currently edit, the British Journal of Psychiatry, stated right from the beginning of his editorship that insanity was a disease of the brain (Bucknill, 1856), and as this hypothesis was first expressed by Hippocrates it cannot be ignored. The way psychiatry has developed in the past 150 years has shown that a simple disease model is not adequate to explain everything we know about mental health and illness, and at various times other models have entered the fray.

We all like to have a coherent basis for our actions; professionals in mental health, and this includes many disciplines – psychiatrists, psychologists, mental health nurses, occupational therapists, social workers, and care workers of all types – are no exception in wishing to have a clear underpinning philosophy behind what we do. Most of these practitioners, usually implicitly, adopt one of the models discussed in the following pages. Explicitly they may claim that they come to a considered judgement on each clinical issue and adopt the appropriate model for that judgement. This is commonly described as being ‘eclectic’. Now eclectic means ‘deriving ideas from different sources’ and although it sounds impressive it describes neither a model nor a philosophy. In practice there is a danger that the eclectic follows admitted or undeclared prejudices without realizing what these are. It allows a luxury of change without necessarily giving a reason for this and is not far short of dilettantism, the adoption of different models almost as a whim.

Models cause psychiatrists endless trouble and none of the models of mental illness described in this is so neat and elegant that it covers everything. Each of them conveniently leaves out the rough pieces that do not fit and the search is still on for a model that is truly comprehensive and can be applied universally. The Dean who interviewed our medical student almost certainly belonged to the group who consider psychiatry to be a ‘soft’ branch of medicine in which the theoretical framework for treatment is poor, there are too many disparate treatments, and there is much argument between practitioners, and this probably explains the fundamental prejudice towards psychiatry that still lies behind the subject in medicine (Bolton, 2012), and which is shared by the general population. We have just completed a study of a common condition, health anxiety, in medical patients attending five different types of clinic in general hospitals. We saw nearly 30,000 patients and 5747 (19%) of these had abnormal health anxiety (that is, it created considerable concern, worry and handicap) (Tyrer et al., 2011). We offered those who had high levels of health anxiety the opportunity of taking part in a randomized trial of a new psychological treatment for this condition. Fewer than one in 12 (444) of these, agreed to take part or were excluded for other reasons. I would like the reader to hazard a guess how many of 5747 patients suffering from cancer, or indeed Alzheimer’s disease, would respond if asked to take part in a trial of a new treatment for their condition. Whatever your guess, I am sure it would be much higher than 8%. The reasons people gave for not taking part in our trial included a mix of denial (there is nothing wrong with me that the proper doctors cannot sort out), shame (I do not need any special help and should be able to sort this out on my own), fear (I don’t trust these new-fangled psychological treatments), and prejudice (I won’t have anything to do with mental health services). My view is that stigma, discrimination and ignorance of mental health by many outside the subject is related to the models that are discussed in this book. Unfortunately, some of this prejudice is related to the oldest model of all, that mental illness is a form of degeneracy, a rotting of the brain that has no cure, only primitive forms of alleviation. This was the view of mental illness by many so-called experts in the nineteenth century which has unfortunately persisted, particularly in less-developed communities, to the present day, and which explains why in many low-income countries mental health receives less than 1% of the total health budget.

In each of Chapters 2–5 one of the models is described in its most favourable light. Chapter 2 chapter will look at mental disorders in which the cause, clinical manifestations, pathology and treatment of many organic illnesses seem now to be very well known and so are admirably suited to the disease model. Unfortunately, as we shall find, the disease model creates tremendous antipathy among many other mental health professionals who have been trained in different ways and seems to have no bearing on their practice. They are using one or more different models, each of them creating some antipathy in others, and if they are not exposed and compared, there will be confusion and continued argument, and our medical school Dean will have more justification for his arguments.

So rather than present a cosmetic repair of the schisms in psychiatric thought, in this book we are exposing these divisions from the beginning. In the following chapters we leave each model to speak for itself in explaining the cause, pathology and treatment of a number of mental disorders and show how each is interpreted using the model under consideration. An adversarial approach is used here. Each model is presented to its best advantage and the other models criticized for their less satisfactory positions. We recognize this may make each model a little two-dimensional and look like a caricature of the real thing. However, we hope that by exposing the conflict between different models the reason for their relative persistence becomes clear and there is much greater understanding between those who hold to one model at the expense of others. It should also help the reader to understand the philosophy of those who particularly adhere to one model or another and find that it suits most of their needs. It also prepares the reader for the integrated model in the final chapter. We do not pretend that the synthesis here is going to satisfy everybody but at least it offers a framework for use in practice, and I feel after 40 years of practice that it is the best working model available, even though, as you will read, it still creates controversy. The very fact that so many models for mental disorder still exist shows that there is a place for all of them. But in time a unified approach will have to come.

‘Models cause psychiatrists endless trouble . . .’

What is described here is hardly new. Siegler and Osmond in 1974 described six different models: medical, moral, psychoanalytic, family, conspiratorial and social, and came down very heavily in favour of the medical model. We have confined our attention to four: the disease, psychodynamic, cognitive-behavioural and social models. The reason why we have done this is that in clinical practice each of the models goes about treatment in a different way and therefore shows the differences between each model in ordinary practice. You will note that we have not used the term ‘medical model’. We agree with Bursten (1979) that this adjective is a confusing and unnecessary one. It gives more attention to the practitioner (a doctor) than this description, and because it does not actually describe the type of model, it can be manipulated to suit any taste. However, we accept that some people might regard the final synthesis that we present later in this book as a true medical model and this is fairly close to what has been called the bio-psychosocial model following the pioneering suggestions of George Engel over 35 years ago (Engel, 1977).

This is not intended to be a short textbook of psychiatry but could be seen as a philosophical introduction around the subject. We are dealing here with ideas, views and opinions, and these are no substitute for the bricks and mortar of hard fact. However, each model has to be tested in the factual world and we expose each one to scrutiny in this way. Our main aim is the practical one of making sense of the presentation in mental illness. At its simplest level we are trying to teach a sorting operation, rather like the tests often given to young children, when they are required to separate a number of articles on the basis of shape, size or colour. If this book serves its purpose it should be possible to identify each new piece of psychiatric information and place it with the appropriate model. There should be little difficulty in identifying the right model for a particular description or interpretation, although this is sometimes hard to decipher in the use of psychiatric jargon. So Lady Macbeth’s question ‘cans’t thou not minister to a mind diseased, pluck from the heart a rooted sorrow?’ can be seen easily as a question from the psychodynamic model, even though Shakespeare had no idea what this model was – although some say he was the first psychoanalyst. The idea that a deeply rooted mental problem can cause current distress is one of the fundamental tenets of the psychodynamic model and it is clear that Lady Macbeth is looking for such an answer in asking her question. This view receives confirmation later in the play when she declares ‘throw physic to the dogs, I’ll none of it’. This clear rejection of the disease model in favour of the psychodynamic one is entirely consistent.

Similarly, when Hamlet says, ‘how strange or odd soe’er I bear myself, as I perchance hereafter shall think meet, to put an antic disposition on’, he is following the ideas behind the social model. He is trying to find a solution to the mad incestuous relationships going on in his family but it is not he who is mad, but the Danish court environment in Elsinore.

Of course this sorting process is only the first stage in using models properly. The hackneyed phrase ‘I can see where you are coming from’ describes the recognition and identification of the model being used. Once we identify the correct model, instead of a pot-pourri of isolated facts and opinions, we can understand the coherence and the belief systems that lie behind statements, opinions and the interpretation of events and symptoms in mental disorder. Because treatment is so closely linked to each model the disturbingly large range of therapies competing with each other in psychiatry also comes into perspective. In guiding the practitioner and patient to a synthesis of these models we recognize that each individual has to make a personal synthesis. This is an exercise that demands a great deal but may well repay amply in the long term. We are not expecting every reader to get to the stage of making a personal model of mental disorder but at least those views that are already held will be recognized as components of a model rather than nuggets of truth. Both an honest self-assessment and understanding of the various ways in which psychiatry is practised are the first steps in getting to grips with the subject. We hope it will develop a common language of understanding so that mental health workers can understand each other, students and aspiring clinicians can understand them, and patients, clients or users (however we wish to describe them according to which model we use) can understand what on earth is going on when they puzzle about the motives and actions of their therapists.

Since the first edition of this book in 1987 users of mental health services have gained enormously in power. Recently I became aware of this when I complained to the hospital management that one of the patients on the ward I was looking after was creating many problems for other patients and really should be moved elsewhere. My request was ignored but when I suggested to the most vulnerable patient concerned that she made the request it was acted on immediately. ‘Doctor knows best’ has not yet been replaced with ‘patient knows best’ but there is now much greater awareness of the need to involve patients (I’m sorry I still find it very difficult to use the term ‘service users’ as the alternative here) in our decisions and the reasons for them. One of the commonest phrases in clinical research is ‘informed consent’. This describes the understanding of the subject that what is being carried out is fully appreciated and agreed to by them and signed accordingly. Mental health workers are much better practitioners if they also have informed consent from the subjects that they treat. This is not a restricted exercise in which only a small part of the reasons for treatment are shared. Ideally it should explain the models being used so that the patient can act with reciprocity, the real underpinning of properly informed consent. Listening to the patient is the first part of model development; explaining to the patient using the same model, or contradicting it by introducing another, is a necessary precursor to getting agreement over treatment.

So now we would like the reader to take on the role of spectator observing a play. In each of the next four chapters the actors have different roles. Some may resonate more positively than others but all can be said to be viable. The model army is now on display.

REFERENCES

Bolton, J. (2012) ‘We’ve got another one for you!’ Liaison psychiatry’s experience of stigma towards patients with mental illness and mental health professionals. The Psychiatrist, 36, 450–454.

Bucknill, J.C. (1856) The diagnosis of insanity. British Journal of Psychiatry, 2, 229–245.

Bursten, B. (1979) Psychiatry and the rhetoric of models. American Journal of Psychiatry, 136, 661–665.

Engel, G.L. (1977) The need for a new medical model: a challenge for medicine. Science, 196, 129–136.

Siegler, N. and Osmond, H. (1974) Models of Madness: Models of Medicine. Macmillan, New York.

Tyrer, P., Cooper, S., Crawford, M., et al. (2011). Prevalence of health anxiety problems in medical clinics. Journal of Psychosomatic Research, 71, 392–394.

THE DISEASE MODEL

‘The main claim of the physical approach, that is the assumption that mental disorders are dependent on physiological changes, is that it is a useful working hypothesis. It has made great advances and looks like making more. It is in line with the main front of biological advance. It is here where psychiatry belongs.’

‘I don’t operate on the same wavelength as he does. He sees everybody as a walking brain.’

How do we reconcile these two extreme views? One, written at a time when psychoanalysis was the main headline grabber in psychiatry, now seems eminently reasonable. Any abnormality of the mind must ultimately have its origin in some malfunction of pathophysiology of the nervous system, and if we were able to elucidate this it would both help our understanding and promote its correction. The second indicates frustration with this approach when it is carried out to what is perceived as an absurd or excessive degree. Does the concentration on pathophysiology prevent understanding of the person? The proponent of the disease model says ‘No, this is nonsense. The person coming to see me wants a problem sorted out. It is my job to isolate this problem from the rest of the person and try and solve it, not to take the whole person into the reckoning. This only dilutes the focus of my enquiry and provides nothing of real use’.

Eight years ago there was a policy in the United Kingdom called ‘New Ways of Working’. This was an initiative supported by the Royal College of Psychiatrists and the National Institute for Mental Health in England (2005), in which the position of the psychiatrist was downgraded to that of ‘team member’ only. This of course was described in Orwellian Newspeak as a ‘new model of distributed responsibility and leadership’, but the message was clear, the special skills of the psychiatrist, as a doctor specializing in mental disorders, were being downgraded. The diktat was, ‘Just as we may need an occupational therapist to advise us on the daily activities of a patient, we may need you as a psychiatrist from time to time to say something about diagnosis’.

Not surprisingly, this message did not go down well with psychiatrists who considered that mental illness was indeed brain disease and needed the special knowledge of people trained in this discipline. So 37 of the psychiatrists got together and wrote a special article which was published in the British Journal of Psychiatry. Entitled ‘A wake-up call for British psychiatry’, it spelt out exactly what should be expected from psychiatrists when they were asked to assess patients. The two paragraphs below summarize the essentials of their argument, and although the writers were not specifically promoting the disease model – as you will note that they were generous in allowing other approaches to be considered – they did put their fingers on the number of the problem. Unless you know about proper disease in the way that other doctors appreciate it, you cannot say that an adequate mental health assessment leading to a coherent treatment plan can be created by another health professional.

‘Psychiatry is a medical specialty. We believe that psychiatry should behave like other medical specialties. When a general practitioner is confident that a psychiatric assessment is not needed, it should be possible for a referral to be made directly to a relevant non-psychiatric professional. However, where the general practitioner is unclear about diagnosis or treatment, the patient should be assessed by the most appropriately skilled and experienced professional on the team, the psychiatrist. This is analogous to managing back pain, where in many instances a general practitioner is confident that a medical orthopaedic opinion is not needed and will refer directly to a physiotherapist or an alternative therapist such as an osteopath or chiropractor. However, in severe, persistent or otherwise complex cases an orthopaedic referral should be made, because an assessment by an orthopaedic surgeon is required to ensure accurate diagnosis and exclude or treat causes that are remediable, thereby improving the patient’s quality of life and minimizing the risk of complications such as paralysis.

In psychiatry, it is psychiatrists, who are trained in diagnosing physical and mental illness, who are competent to formulate diagnoses that incorporate physical, mental and social factors and, where appropriate, recommend initiation of one or more of a range of possible medical treatments. As in other medical specialties, initial assessment may also involve important contributions from other non-medical members of the team, and may include relevant medical investigations such as blood tests or imaging investigations. Assessment, in many cases, may lead the psychiatrist, as a leader in the clinical team, to conclude that the most suitable treatment is a psychological or social intervention delivered by the member of the team with the most appropriate skills. This approach allows the patient the benefit of a thorough, broad-based assessment by a highly trained professional in order that the most appropriate management is implemented at the earliest opportunity’.

The rest of this chapter puts more flesh on the bones of this argument, and has the merit of being able to draw on over 2000 years of experience with the disease model in medicine.

WHAT IS DISEASE?

The name ‘mental illness’ implies disease, and wrapping it up in euphemistic terms such as ‘mental health problems’ is only a temporary disguise. An illness suggests that there is a fundamental impairment of normal function and is not just a normal variation. The disease model regards mental malfunction as a consequence of physical and chemical changes primarily in the brain but sometimes in other parts of the nervous system. It is a model that has served general medicine extremely well over the last millennium and has made dramatic strides in the past 200 years. Unless it is implied that in mental illness there are different rules that apply to the recognition of illness than in other parts of medicine, we have to adopt the same approach. Thus we have to conclude that in all mental illness there is impaired function and some pathological change in one or more parts of the body.

The definition of disease in this context has been defined by Scadding (1967) as ‘the sum of the abnormal phenomena displayed by a group of living organisms in association with a specified common characteristic or set of characteristics by which they differ from the norm for their species in such a way as to place them at a biological disadvantage’. This definition is equally suited to physical and mental disease and is important because it sets limits to illness. In psychiatry, for example, there is much concern over the medicalization of illness by the introduction of new conditions such as ‘late luteal dysphoric disorder’ (pre-menstrual tension to you and me) and ‘social anxiety disorder’ (a touch of shyness) that are not necessarily biologically disadvantageous and which merge imperceptibly into normal health variation. The disease model in psychiatry helps to decide which of these conditions is beyond its scope and unsuitable for mental health interventions.

STAGES OF IDENTIFICATION OF DISEASE

1 The description of symptoms and main features of the disorder (the clinical syndrome)

2 Identification of pathology (i.e. the structural or biological changes created by the illness)

3 Study of the course (natural history) of the syndrome

4 Determination of its cause or causes.

FOUR TENETS OF THE DISEASE MODEL

Mental pathology is always accompanied by physical pathology
The classification of this pathology allows mental illness to be classified into different disorders which have characteristic common features
Mental illness is handicapping and biologically disadvantageous
Cause of mental illness is explicable by its physical consequences

Management or treatment based on the pathology of illness and its outcome following that treatment (prognosis) can also be considered as part of the model. But if every other stage is properly elucidated these will follow automatically. These stages can only be regarded as logical if four tenets of mental illness are accepted (Box 2.1).

STAGE 1 – IDENTIFICATION OF THE CLINICAL SYNDROME

Almost invariably the recognition of a clinical syndrome is the first stage in the identification of an illness. This begins by first noting ‘an association of signs and symptoms’ (signs being observed abnormalities or those identified on examination and symptoms being complaints or felt changes in function). Thus certain symptoms such as loss of appetite and lack of energy, or objective signs such as a rapid pulse and an enlarged thyroid gland, tend to be linked to certain illnesses. Once the investigator’s mind is alerted to this link other symptoms or signs are identified until the complete syndrome is found. The persistent association of two symptoms or signs may be a chance finding, three is likely to imply a real association, and four confirms it. Observation is the hallmark of correct identification of the syndrome and depends on clinical skills alone. The different elements of the syndrome may have no obvious meaning at first but they will all have to be accounted for if a syndrome is to achieve the status of a disease. Doctors such as Sydenham and Bright in the eighteenth century were excellent examples of medical detectives who identified new important syndromes, and unlike modern doctors they did not have the technology of the laboratory to help them in their task. Psychiatry is not that much further on than we were in eighteenth century and many of our ‘diseases’ are provisional ones in which several current combined diagnoses (often called comorbidity) may need to be joined together when their real nature has been elucidated.

The great fictional detective, Sherlock Holmes, was modelled by Arthur Conan Doyle on the clinical skills of a well-known Scottish physician, Sir Charles Bell, who was famed for his ability to diagnose medical conditions from small tell-tale signs that no-one else had noticed, which he used to display with a flourish when teaching medical students. So ‘Elementary, my dear Watson’, could well have come directly from one of these dramatic teaching sessions when a hapless student was used as a foil for the great diagnostician.

Through clinical observation (and interrogation) such doctors identified diseases which were only shown to have the other attributes of the disease model many years later. For example, acute Bright’s disease is an inflammation of the kidney (nephritis), first described in 1827. Bright suspected that the syndrome of fever, swelling of the face and hands and little or no flow of urine (anuria) was likely to involve the kidney, but until he linked all the clinical symptoms together the illness went unrecognized. It was many years later before the microscopic pathology (an inflammation of certain structures (glomeruli) of the kidney) and the cause (hypersensitivity to certain strains of a bacterium (the haemolytic streptococcus)) were discovered, but it was Bright who first focused the eyes of science on the problem.

Clinical syndromes are later refined into diagnoses, which are really convenient code names for the syndromes. So when doctors talk together about a patient with thyrotoxicosis (Graves’ disease) they are telling each other in one word that the patient has a syndrome which is likely to include an enlarged thyroid gland (goitre) together with atypical facial appearance, loss of weight, abnormal trembling, special eye signs, rapid heartbeat, increased speed of reflexes, and nervousness. The diagnosis of an illness may not be confirmed until other tests (usually carried out in a laboratory) are also consistent with the disease in question but the important part of the diagnostic process is the clinical assessment of the patient, and a clinical diagnosis can stand independently of laboratory findings.

The clinical syndrome is elicited mainly from a detailed history from the patient and a careful physical examination. The history gives strong clues about the possible nature of the complaint, so the doctor is sensitized to pay special attention to certain features when he carries out his examination. Because a history can be unreliable or may omit important changes he or she should always carry out a full physical examination; even if an abnormality expected from the history is identified other abnormal signs may be missed unless all systems are examined.

Taking the history

Every medical student learns this basic approach at an early stage in training; it is also expected by the general public. Psychiatrists who follow the disease model have a very similar approach in assessing mental symptoms using the same techniques as with physical ones. The first stage is a careful history which is more detailed and usually takes longer than a medical history. This is because the background of the patient, his personal and family history and antecedent events are assessed as well as any relevant medical and psychiatric history. All psychiatrists, whatever model they adopt, have to take the whole person into account in making an assessment, and because they are often thinking about the complexities of possible syndromes when they are doing their assessments, they may appear to be impersonal and unaware of their potential to induce distress.

The good clinicians of the past were all too well aware of the importance of good interaction with their patients, but they had the advantage of less knowledge and very little in the way of useful interventions. Indeed, as Dr Jonathan Miller has noted in his television presentations of the history of medicine, before 1900 the practice of medicine involved virtually no effective treatments whatsoever apart from the clever manipulation of placebos (interventions that did no harm but made the person feel better, even if only temporarily).

Although every doctor is now taught diligently about the importance of communication skills it is not always necessary to take on all the tenets of what is commonly called the ‘holistic approach’ when focused on disease. If you consult a doctor for removal of a wart (verruca) on your finger you might take exception to a set of searching questions about your personal and sexual life on the grounds that this information was irrelevant to wart removal.

(Of course it might not be irrelevant if the wart was elsewhere.) The psychiatrist who follows the disease model is sometimes criticized for not thinking of the patient as a person, but as a ’case’. The criticism, which is common in other branches of medicine, is only justified if the doctor treats the problem wrongly because of inadequate assessment. The psychiatrist who looks on a mental disorder as a brain disease cannot afford to neglect a full history of past and present problems as this gives important clues to the nature of the disorder. Where he will differ from his colleagues who follow different models is that his questions will be more formalized and the interactional part of the interview ignored. The interview is regarded as an exercise to gain information instead of the first phase in a significant personal relationship.

Examining the patient

The physical examination is carried out in the same way as in other medical conditions, and is an essential part of the assessment of every psychiatric patient, even though it may provide no additional information, as only a few psychiatric disorders have obviously abnormal physical signs. Some psychiatrists disregard a physical examination on the grounds that they are only specialists in mental health. This annoys the disease psychiatrist. The late Dr Richard Hunter, one of the strongest adherents to the disease model, attacks this view in trenchant terms, ’Psychiatrists do not diagnose their patients like other doctors do. They discard four of their senses and literally play it by ear. It is the no-touch technique adapted to new purpose. Physical examination or laboratory investigation, which transformed medicine from guesswork and theory to fact and science, are spurned or positively discouraged. It is alleged that they deflect attention from study in depth of the patient’s mind, and impede rapport’ (Hunter, 1973). This is an interesting point – talking about symptoms in a formal way and examining the body systematically may not seem to be the best way to develop a good caring and sharing relationship with a patient – but it is regarded as essential in the disease model in order to avoid missing important pathology that could never be detected by the most perfect of professional relationships.