Proving and Disproving Psychiatric Injury

Transcription

1 Proving and Disproving Psychiatric Injury Dr David Gill Consultant Psychiatrist, Hertfordshire Partnership NHS Foundation Trust Introduction If a claimant who has been exposed to trauma describes psychiatric symptoms to a psychiatrist accepted by the court as an expert, who then reports that the claimant has, say, post-traumatic stress disorder caused by the litigated event, has the claimant proved the medical aspect of his case? Not necessarily. In this article, I will attempt to set out some of the hidden medical assumptions upon which such psychiatric reports are commonly based. This may offer some hints to lawyers about potential weak spots in psychiatric reports, and how to attack or resist attack upon them. Personal injury and employment tribunal cases are the main legal arenas in which psychiatric injury is important. Personal injury, for example from work or traffic accidents, is associated with more dramatic conditions, such as post traumatic stress disorder. On the other hand, employment cases tend to involve claims of long-term adverse treatment rather than sudden individual events, and so tend to be associated with claims for depression and anxiety. However, both types of case need an expert report from a psychiatrist, or psychologist. I have three main points. 1. Psychiatric Classifications In days gone by, the court or tribunal might have accepted the opinion of an expert based partly or even mainly on personal authority. The Meadow case perhaps illustrates, amongst other things, the drawbacks of such an approach to medical experts. The court is thus unlikely now to defer to an individual psychiatrist about whether psychiatric symptoms constitute a psychiatric injury according to his own individual and potentially idiosyncratic definition thereof. Latterly, the courts have accepted that a psychiatric injury for their purposes is defined by whether the symptoms claimed constitute a recognised psychiatric diagnosis set out in one of the two main classifications of psychiatric disorder, the DSM-IV-TR of the American Psychiatric Association, 1 or the ICD10 of the World Health Organisation. 2 But these classifications were not designed and validated for medico-legal purposes, but for research and clinical use. Hence, the use of DSM-IV and ICD10 in reports for the courts potentially raises issues, seldom mentioned in the reports themselves, which I will attempt at least to touch upon below. 2. Epidemiology Epidemiology is the science of diseases in populations. Although the discipline of psychiatric epidemiology is well developed, it comes up in medicolegal cases surprisingly rarely, even though it is potentially relevant. For example, let us consider a flock of sheep. What percentage x have been traumatically chased by the fox? And what percentage y have gone on to develop post traumatic sheep disorder? I will say at this point that community surveys invariably show that x is much greater than y, suggesting that factors other than the trauma may play a role in the genesis of psychiatric injury.

2 3. Methods of Assessment I will say a little about the usual process of psychiatric assessment and report preparation, its strengths and weaknesses and, in particular, whether recent advances in techniques for assessing the validity of claimants symptoms (known as effort testing) form a useful addition to the assessment process. Psychiatric Classifications Recognised Psychiatric Injury As indicated above, the court or tribunal has come to consider the question of whether psychiatric symptoms constitute a psychiatric injury or not in terms of whether the symptoms claimed constitute a recognised diagnosis under the DSM-IV-TR of the American Psychiatric Association, or the ICD10 of the World Health Organisation. In the classifications, the various conditions are described succinctly in bullet point form; for example, let us consider the description of depressive episode, from the ICD10. By depressive episode, is meant a period of diagnosable clinical depression: F32 Depressive episode In typical mild, moderate, or severe depressive episodes, the patient suffers from lowering of mood, reduction of energy, and decrease in activity. Capacity for enjoyment, interest, and concentration is reduced, and marked tiredness after even minimum effort is common. Sleep is usually disturbed and appetite diminished. Self-esteem and self-confidence are almost always reduced and, even in the mild form, some ideas of guilt or worthlessness are often present. The lowered mood varies little from day to day, is unresponsive to circumstances and may be accompanied by so-called somatic symptoms, such as loss of interest and pleasurable feelings, waking in the morning several hours before the usual time, depression worst in the morning, marked psychomotor retardation, agitation, loss of appetite, weight loss, and loss of libido. Depending upon the number and severity of the symptoms, a depressive episode may be specified as mild, moderate or severe. For a mild episode, the ICD10 says that two or three of the above symptoms are required; for a moderate episode, four or more, and for a severe episode, several symptoms plus other features are required. Claimant, Diagnose Thyself? There is nothing to stop the claimant or his friend or relative or lawyer from looking up the above description on the internet, where it is freely available, and coming to his own diagnosis. Certainly, the plain, non-technical language is readily understandable by the layman, making the exercise at least technically feasible. Yet the court still seems to insist on the trouble and expense of having a psychiatric expert. This must imply that the court does not consider in fact the ICD10 and DSM-IV-TR are mere checklists for their purposes. The Role of the Expert It follows, then, that the court must be expecting the psychiatric expert to do more than merely tick boxes. It is to be presumed, therefore, that he is expected to interpret his clinical findings for the court, not only in relation to the criteria set out in the classifications for each diagnosis, but also in relation to other relevant factors, including the general cautions set out in the classifications regarding medicolegal use.

3 It seems to me, therefore, that the court is looking to the psychiatric expert, as an experienced clinician: to evaluate the claimant s account and other information to hand; to consider all the circumstances; to bring to bear his skill and training; to relate this to his daily experience of real-life clinical practice; and to interpret this in relation to the psychiatric classifications. A psychiatric report may be considered of less assistance to the court if it confines itself to a narrow approach based on ticking the boxes in the classifications, and does not include consideration of these perspectives. True and Complete The practice direction to Part 35 of the CPR indicates that expert is under a duty to provide his true and complete professional opinion. 3 The ultra cautious expert might say that he is on the safest ground if he sticks, as it were, to his box ticking, and leaves out any more general appreciation of the claimant; he then can be sure that his opinion is at least in a technical sense true. But it seems to me that the duty to provide a complete opinion means that the expert cannot rightly exclude holistic considerations of the claimant, which he may gain from the hurly-burly of daily clinical practice. For example, I work for the National Health Service as a general psychiatrist in a deprived area, with high levels of poverty, social problems and psychiatric morbidity. In my NHS clinics, I hardly ever come across patients with post-traumatic stress disorder from road traffic accidents, or driving phobia from the same, or post-concussional syndrome from minor blows to the head. Yet I frequently come across claimants in my medico-legal work who are claiming to have been disabled by such injuries. Inspection of their notes reveals that their cases usually have their existence mainly in a medico-legal world of experts and CBT therapists. They almost never receive the same level of NHS care as patients who have disabling mental disorders such as schizophrenia (who may receive long-acting injections of medication because they cannot be relied upon to take tablets, who may live in a supported accommodation because they cannot look after themselves, and who will be seeing not only a psychiatrist in outpatients, but will also have a care coordinator, either a community psychiatric nurse or social worker, to take charge of their care, including in some cases their money). In my view, such real-world perspectives must have a place in expert reports for the court, particularly in the assessment of whether a diagnosed psychiatric injury should be accepted as the cause of disability. In other words, the psychiatrist must wear the same hat in his medico-legal work as he does in his NHS work. If in his NHS work, he would have at least some degree of scepticism about whether a small or even trivial cause could be accepted, whatever the clinical picture presented, as producing a very large effect in the way of psychiatric symptoms and disability, it is difficult to see how such considerations could properly be completely excluded from medico-legal reports. Hence, simplistic adoption of a checklist approach to the symptoms listed in the classifications as the basis of the diagnosis of a psychiatric injury, will tend to emphasise the claimant s account of his symptoms and difficulties, whilst potentially relevant background factors will tend to be under emphasised. As the DSM Introduction puts it: 1

4 In most situations, the clinical diagnosis of a DSM-IV mental disorder is not sufficient to establish the existence for legal purposes of a mental disorder, mental disability, mental disease, or mental defect. In determining whether an individual meets a specified legal standard (e.g., for competence, criminal responsibility, or disability), additional information is usually required beyond that contained in the DSM-IV diagnosis. This might include information about the individual s functional impairments and how these impairments affect the particular abilities in question. It is precisely because impairments, abilities, and disabilities vary widely within each diagnostic category that assignment of a particular diagnosis does not imply a specific level of impairment or disability. Other Woolf Considerations As well as the duty to give a true and complete opinion, there are a couple of other duties of the expert under the CPR which appear to me to be seldom fully covered by psychiatric experts and I am probably as open to criticism in these respects as my peers. These duties are to discuss the likely range of professional opinion, and the related duty to mention factors which might detract from the opinion expressed. If the expert does not discuss the likely range of reasonable opinion, it gives rise to the supposition that he must consider his own view as the only possible one; presumably this would be hard to sustain in the face of legal questioning, in such a subjective area as psychiatry. Factors which might conflict with the opinion expressed is obviously a related matter. Again, if there are such obvious factors which are then ignored by the expert, this might weaken his report. This is because it would then look as if he had left them out, because he was afraid that if he put them in, his opinion would be untenable. In fact, complete consistency of information in psychiatry would be unusual, and might almost be considered too good to be true. As with an ancient mosaic, a few tesserae can be discrepant, without obscuring the picture; perhaps, indeed, they add some realism. Medico-Legal Cautions in the Psychiatric Classifications As Shakespeare said, The devil can cite Scripture for his purpose. 4 Perhaps that is putting it a little strongly, but the point I am making is that the classifications were not designed for medicolegal use. As we have seen, they are divided into chapters, which contain descriptions of the various conditions, with lists of clinical features, and inevitably these have come to be seen as diagnostic checklist. Such a checklist approach has the attraction of reliability, in that different clinicians are more likely to record the same clinical features in the same patient, and therefore come to the same diagnosis. However, while it may gain on the swings of reliability, a checklist approach tends to lose on the roundabout of validity, because there is no tick box in which the clinician can record such matters as contextual information, commonsense, and clinical experience. Classifications of Psychiatric Disorder: Historical Background A little history may help to explain the current psychiatric classifications preference for reliability, in the form of checklists, over validity. (I will concentrate here on the DSM, as it is more well-developed than the ICD, at least partly because the ICD covers the whole of medicine not just mental health.) The watershed in the development of the current classifications was the third edition of the DSM, the DSM III, which came out in Subsequent editions of both classifications, the DSM-IV, DSM-IV-TR (Text Revision) and the ICD10, are to a large extent developments of the DSM III.

5 Before DSM III, American psychiatry was dominated by the psychoanalytic school, through the strong influence over two or three generations of a cohort of continental psychiatrists who had been refugees from National Socialism. Diagnoses according to its predecessor, the DSM II, may have been richer in context and background, but were not very reliable, so that by the 1970s, it had become embarrassingly clear that the same patient could be seen by two psychiatrists, who would come up with, according to DSM II, completely different diagnoses. By this time, the US had put a man on the moon, and was ready for a more scientific approach, which was duly promulgated in 1980 in the DSM III. DSM III 1980: Introduction of PTSD and Major Depressive Episode These two conditions, which were new in DSM III, can be seen as its hallmarks. They both seem to depend, at least on a superficial reading, on a checklist approach. For example here are some of the criteria for post-traumatic stress disorder, as often quoted in reports: Criterion A exposure to a traumatic stressor. Criterion B re-experiencing symptoms. Criterion C avoidance and numbing symptoms. Criterion D symptoms of increased arousal. It looks terribly straightforward, at first sight. But in fact, the American Psychiatric Association committees which produced DSM III seem to have been very well aware of the pitfalls of such lists, and introduced into the DSM a number of cautions to try to form a counterweight to the inevitable ensuing tendency toward tickboxing. Checks and Balances in the DSM-IV These qualifications, which are set out in the Introduction to the DSM-IV, are widely ignored by psychiatric experts. Of course, when a reference book runs to several hundred closely printed pages, very few people actually read an introduction which itself goes on for 40. But the Introduction, which would perhaps be better termed a Guide or Key to the following chapters, is a necessary part of proper use of the DSM. Here are some key points. In general: It is important that DSM-IV not be applied mechanically by untrained individuals. The specific diagnostic criteria included in DSM-IV are meant to serve as guidelines to be informed by clinical judgment and are not meant to be used in a cookbook fashion. Regarding medicolegal use in general: When the DSM-IV categories, criteria, and textual descriptions are employed for forensic purposes, there are significant risks that diagnostic information will be misused or misunderstood. These dangers arise because of the imperfect fit between the questions of ultimate concern to the law and the information contained in a clinical diagnosis. Regarding natural reactions: this syndrome or pattern must not be merely an expectable and culturally sanctioned response to a particular event As for malingering, the DSM faces this important issue squarely, not only in its definition of it but also in its descriptions of the individual conditions. For example, the following sentence comes from the chapter on PTSD:

6 malingering should be ruled out in those situations in which financial remuneration, benefit eligibility, and forensic determinations play a role This is just as much a part of the definition of PTSD according to DSM as in the familiar criterion A, etc, quoted above, yet I have never seen it quoted in reports. Similar rarely quoted cautions about excluding malingering are given in the definition of other psychiatric disorders. Malingering in the DSM The DSM does not give details about how malingering should be ruled out. Presumably it is leaving it to the expertise of the psychiatrist, or deferring to the court, or some combination of the two. A definition of malingering itself is included in the DSM-IV, not as a mental disorder, but under Other Conditions That May Be a Focus of Clinical Attention V65.2 Malingering. The definition given in fact sets a very low bar: according to DSM, malingering should be strongly suspected when two or more of the following factors apply: 1. medico-legal context, 2. antisocial personality disorder, 3. discrepancy between complaints and objective findings, and 4. lack of co-operation with the assessment. In effect, DSM is thus advising that it should be strongly suspected in any disputed medicolegal case (where points 1 and 3 apply). DSM s Five Axes Cover More Than Just the Psychiatric Injury In reports where DSM is used, mostly one just sees Axis I referred to, which is understandable, because it is on this Axis that episodes of mental illness are, in the jargon, coded (and psychiatric injuries are episodes of mental illness). However, there is more to the DSM than that. It has five axes, not just one, which I now briefly describe. Axis I: for mental illnesses, an illness being defined as a state of impaired health with a clear onset following a period of normal function. Axis II: Personality Disorders and learning disability (formerly called Mental Retardation); here, the abnormalities are permanent, and are apparent from adolescence or earlier. Clearly, personality difficulties can affect response to adverse events. Axis III: Physical health problems. Axis IV: Psychosocial and Environmental Problems: this axis is for reporting psychosocial and environmental stressors that may affect the diagnosis, treatment, and prognosis of mental disorders. Axis V: Global Assessment of Functioning Scale is for reporting the clinician s judgment of the individual s overall level of functioning and carrying out activities of daily living. This information is useful in planning treatment and measuring its impact, and in predicting outcome. As indicated, what is usually given in a psychiatric report is a diagnosis of a mental illness such as for example post-traumatic stress disorder, with the numerical code (I would suggest that, in passing, we note that the use of such precise numbers can give an impression of unassailable scientific precision which, of course, in context, is entirely spurious.) But post-traumatic stress disorder is only axis I. If the person had a marked constitutional tendency to anxiety, this would be coded on axis II.

7 If they had a physical health condition, such as for example a painful injury, it will be coded on axis III. If they have psychosocial problems such as for example poverty, unemployment or family difficulties, this will be coded on axis IV. Hence, just to pile everything onto an Axis I diagnosis, and attribute it let us say to an accident, would tend to overemphasise the role of an adverse event, as against background factors coded on the other axes; it could be held to constitute a misuse of the DSM. The importance of this in respect of causation is obvious. Valid Medicolegal Use of DSM-IV: Summary In order to be used properly and defensibly in a psychiatric report, therefore, I would suggest that an author of a report who refers to the DSM needs to include the following: Consideration of the question of illness or natural reaction. Use of all axes, not just Axis I. Response to the DSM s own expressed cautions re: Cookbook use Forensic use Malingering Those evaluating psychiatric reports may wish to look to see if these checks and balances set out in the DSM have been properly considered. Validity Considerations in the ICD10 The ICD10 deals with these questions of validity in a different way. Generally speaking, it is much less well-developed than the DSM, and in particular it does not have anything corresponding to the DSM s detailed Introduction. But there is one very interesting part of the ICD10, particularly when it comes to employment matters, where the ICD10 seems to have given matters more detailed consideration than the DSM-IV. These are the Z codes of the ICD-10, which contain useful descriptors for patients who have come into contact with health services even though the underlying problem is to do with work rather than their health. In fact, I first learned of the existence of the Z codes in the marbled halls of the Croydon Employment tribunal, when my opposite number was asked whether the Z codes offered an alternative to his diagnosis of severe depression, where he had given the F32 code for depressive episode under the ICD10. Of course, he hadn t heard of them either. He went on to give the impression of experiencing some difficulty during cross-examination. These Z codes seem to remain little known amongst psychiatrists. They are indicated by the ICD as non-disease codes. They are given in the next paragraph by way of illustration. Z56 Problems related to employment and unemployment Z56.0 Unemployment, unspecified Z56.1 Change of job Z56.2 Threat of job loss Z56.3 Stressful work schedule Z56.4 Discord with boss and workmates Z56.5 Uncongenial work

8 Difficult conditions at work Z56.6 Other physical and mental strain related to work Z56.7 Other and unspecified problems related to employment Problems in Life: Unhappy or Mentally Ill? To give an example, let us consider a claimant, who has experienced low mood in the context of perceived adverse treatment at work; has he on the one hand developed a mental illness, for example, F32 depressive episode, under the ICD10? Or is he on the other hand unhappy, because of how he feels himself to have been treated, and one of the Z56 codes applies? Surely, not all emotional distress is indicative of mental illness, and some discussion of this point would be expected in a psychiatric report. Rushing to the conclusion that distress necessarily indicates mental illness could constitute a weakness in a report. After all, if the claimant had in fact been subject to bullying or racial discrimination or sexual harassment, how would he be expected to feel? The background to this question is whether the normal ups and downs of life are these days being overdiagnosed as mental health problems, particularly depression. The drug companies have done particularly well out of medicalising such difficulties through the massively increased prescription of antidepressant medications such as Prozac, since the diagnosis of major depression was introduced in DSM III, in effect lowering the bar for the diagnosis. But a previous generation, whether of doctors or patients or employees or employers, would not have given serious consideration to the idea that problems at work, say being passed over for promotion, would be capable of giving rise to disabling mental illness. It is possible that the pendulum has recently started to swing back a little; The Loss of Sadness by two New York sociologists, Horwitz and Wakefield, 5 gives a fascinating description of the background to this question, though it is not light reading. Recent evidence that antidepressants are no more effective than placebo in such mild cases of major depression 6 may lead to re-evaluation of the concept itself; some cases of major depression may in future come once again to be regarded as natural reactions, rather than mental illnesses. The Exact Diagnosis Sometimes in reports, there is extensive discussion of the precise diagnosis. For example, whether the claimant has a depressive episode F32 or on the other hand has F41.2 Mixed anxiety and depressive disorder. This may be important from the medical point of view, for example in planning treatment, but detailed arguments about which precise diagnosis should be arrived at under the DSM or the ICD can generate more heat than light for medicolegal purposes. After all, depression and anxiety are closely related to each other, and overlap, with PTSD and obsessive compulsive disorder being generally seen as sub-types of anxiety, and adjustment disorder as a temporary phase of any of the above. Therefore, excessive detail about the exact psychiatric diagnosis should not be provided at the expense of perhaps more important legal issues such as credibility, causation, effect on function of the condition diagnosed, likely response to treatment and prognosis.

9 Epidemiology Epidemiology of PTSD I now return to our flock of sheep, and will briefly examine some of the research that has been done on the frequency of traumatic events, in this case being chased by the fox, and the frequency of adverse psychiatric consequences. In a large community sample in Detroit, 7.8% of that population had been diagnosable with PTSD at some time in their lives. 7 But no less than 89% had experienced at least one traumatic event, 8 in fact they had experienced an average of 4.8 such events each. Detroit may not be completely typical, but similar results have been found in other surveys. Obviously, part of this discrepancy could be explained by the tendency for such conditions as post-traumatic stress disorder to recover naturally, but other research has indicated that there is much more to post traumatic stress disorder than the traumatic event itself. Spitzer was one of the leading originators of the concept, when it was as it were officially introduced into psychiatry in the third edition of the Diagnostic and Statistical Manual of the American Psychiatric Association, the DSM III, in 1980, of which he was one of the main editors. He wrote in the January 2008 issue of the British Journal of Psychiatry about the problems which have since come to surround the diagnosis: 9 Unlike other diagnoses in the DSM that were agnostic to aetiology, PTSD was defined as a disorder that arose after a specific set of traumatic stressors. Thus, the origins of the definition of PTSD rest on the assumption of a specific aetiology (Criterion A). This assumption, already questionable, has been undermined by reports that the disorder can develop after a variety of non-life threatening events (e.g. divorce, financial difficulties). Further, recent studies have demonstrated the frequent occurrence of PTSD symptoms among people with depression who had not experienced Criterion A life stressors, and among people with social phobias who respond to failed performance situations. Even when an individual encounters horrific, lifethreatening events (Criterion A), studies find that pre-incident vulnerability factors (e.g. psychiatric history) and post-incident social support contribute more to post-trauma morbidity than does the magnitude of the presumed aetiological trauma. In short, Criterion A events are neither necessary nor sufficient to produce PTSD. To summarise, then, one of the chief architects of the DSM III seems to be at least partially resiling from the whole concept of post-traumatic stress disorder which it introduced, and has stated in terms that: Identical clinical states to PTSD can occur without trauma. Traumatic events are neither necessary nor sufficient to produce PTSD. The potential impact on medicolegal cases seems obvious. Hence, recent opinion from one of the originators of the concept of post-traumatic stress disorder reinforces the view that psychiatric reports must look beyond the traumatic event, to factors including the claimant s circumstances pre- and post-accident, and by inference to the possible influence of the legal process itself. Epidemiology of Symptoms Epidemiologists have not only looked at diseases or conditions within populations, they have also examined symptoms. This has essentially involved interviewing normal subjects in the community and asking them about symptoms experienced. The result of such surveys can be summarised very briefly: symptoms in general are extremely common in healthy, community-dwelling subjects.

10 For example, Ihlebaek et al showed in a cross-sectional study of 1,240 normal subjects in Norway, that the prevalence of reporting subjective health complaints was extremely high: 80% reported musculoskeletal complaints, 65% reported pseudoneurological complaints (tiredness, depression, dizziness), 60% gastrointestinal complaints, 34% allergic complaints, and 54% flulike complaints). 10 The vast majority of such symptoms are not caused by physical disease. For example, in the three-year general practice survey of Kroenke & Mangelsdorff: A total of 567 new complaints of chest pain, fatigue, dizziness, headache, oedema, back pain, dyspnea, insomnia, abdominal pain, numbness, impotence, weight loss, cough, and constipation were noted, with 38% of the patients reporting at least one symptom. Although diagnostic testing was performed in more than two thirds of the cases, an organic etiology was demonstrated in only 16%. 11 Epidemiological evidence therefore is that symptoms are extremely common in the community, but the vast majority of such symptoms are not caused by physical disease; such symptoms can be termed medically unexplained symptoms or subjective health complaints. Epidemiology: Summary In summary therefore, we can state that: In normal people in the community, symptoms are the rule rather than the exception, but are usually not caused by organic disease. In claims for such subjective symptoms (psychiatric claims, chronic pain, post-concussional syndrome etc) the question therefore arises might the claimant not have had the symptoms even if the litigated event had not occurred? The role of trauma has been overemphasised unrelated psychosocial factors may be crucial. And there is of course plenty of new disability around based on such subjective symptoms the majority of new Incapacity Benefit claims in the UK are reportedly for common mental disorders such as anxiety and depression. Methods of Assessment Standard Psychiatric Assessment This usually consists of an interview with the claimant, and a friend or relative may also be seen. The medical notes and other papers are then scrutinised, in greater or lesser detail, and the report is written. The clinical assessment is obviously of crucial importance in psychiatry, and is part of psychiatric training from the outset. Any basic textbook of psychiatry will have a description, including a list of standard topics to be covered in the history, the customary subdivisions of the mental state examination, followed by a summary (formerly referred to as a formulation ), diagnosis, differential diagnosis, treatment and prognosis. Bearing in mind that treating psychiatrists frequently have to write reports for Mental Health Act tribunals on detained patients, and that psychiatrists in training often do a placement in forensic (criminal) psychiatry requiring reports for the court, it is likely that a psychiatrist beginning to do medico-legal work on his own account has had at least as good, if not better, a grounding in report-writing as his colleagues in other specialties.

11 Any advantage the beginning psychiatric expert may have in this respect can tend to be cancelled out for medico-legal purposes by the nature of clinical psychiatry, where he will largely be dealing with disadvantaged individuals or families. He has a duty to them, and will routinely give them the benefit of any doubt in the letters he writes at their request to the housing department or the probation service or to whom it may concern. Problems can come, however, when this right clinical inclination is transferred to the medicolegal assessment, where the duty is not to the patient, but to the court to report on the claimant. This can lead in psychiatric reports to overemphasis on what the claimant says at interview, and consequent underemphasis on the medical notes and other documents. There may be unthinking use of direct questioning, which is appropriate in clinical practice to clarify a particular problem, but perhaps less so in medicolegal assessment; the claimant s relatively unprompted account plus the documentary evidence could presumably be seen by a lawyer as a surer basis for diagnosis of a psychiatric injury. Medical records are important in themselves, but also as a comparison with the claimant s account. Obviously, the claimant cannot be expected to remember every consultation from many years ago, but on the other hand he can be expected to give straightforward answers to general questions, for example, about his health before the material event. If he says, for example, that his health was good before the litigated event, but this is directly contradicted by the notes, questions about his credibility as an informant may arise: in this example, there might be concern that he was tending to misattribute pre-existing problems to the litigated matter. Consistency of accounts is important, but on its own is seldom decisive; subjects will naturally vary in their accounts if given successively. Major inconsistency is important, but too perfect consistency might also give rise to doubt. There may be occasions when inconsistencies are so gross as to affect the ability of the medical expert to accept subjective reports as indicative of a psychiatric diagnosis, at least without entering a caveat regarding the court s prior determination of the subject s qualities as a witness. Probably, however, the interpretation of inconsistencies is mainly a legal rather than a medical matter, as the lawyer is trained and experienced in the evaluation of witness testimony. Hence, the role of the psychiatrist here may be mainly to identify the discrepancy in his report. Co-operation with assessment should be noted. Is there, for example, any reasonable medical explanation why a claimant would give a fluent account to his own expert but a very cagey one to his opponent s? The expert could reasonably expect a claimant to be willing to discuss the usual range of topics necessary to be discussed if the interview was a normal clinical interview. Sometimes, however, reluctance to discuss background factors may be encountered. This can be expressed in a simple refusal, I can t see how that s relevant to the accident, doctor, or in more subtle ways. For example, I think you ll find that s all in my notes, which seems superficially reasonable, but is in fact probably inappropriate in most cases: if one is instructed to prepare a report on the claimant, rather than on the papers, it is surely appropriate to ask the claimant for a fresh account of relevant matters. Forms of words can also obscure tendencies to lack of co-operation, for example if the claimant is asked whether he can do a particular daily activity, say driving, and replies vaguely, such as, I really struggle with driving, doctor. Surveillance does not usually produce very dramatic effects on psychiatric reports, since psychiatric conditions are seldom if ever clearly identifiable as present or absent in a black and white sense from outward appearances. Usually, in my experience of video surveillance, the claimant is seen driving to a large grocer s, which he goes round, and then come homes again. The appearances are as it were shades of grey (in every sense), and capable of wide interpretation, except in uncommon cases where the claimant has said that they never drive, or never go shopping, etc.

12 Credibility If the man on the Clapham omnibus read a psychiatric report, I think his first question would be, How do you know they re not just saying that, then, doc? And in medico-legal cases, I think that is a very good question. After all, we know that assessing disability is very difficult, especially if the claim is based on subjective health complaints. For example, Wolfe, one of the originators of the concept of fibromyalgia (or chronic unexplained pain), described a case where no fewer than six doctors considered a patient disabled by chronic pain syndrome; however, once they had seen a video, they all changed their minds. Wolfe commented physicians have a bias toward trust & empathy but (in this case) everyone got it wrong. 12 The claimant in most cases has an incentive to be considered to have a psychiatric injury, and yet we are basing our opinion upon his subjective symptom reporting, mainly. So credibility is crucial. Obviously, deciding the question of credibility is for the court. Nevertheless, it is important for experts to provide the court with any information they have which will help it to decide that question. Traditional Approaches to Assessing Credibility How then do psychiatrists approach this issue? One sees it dealt with in various ways in reports. a) Perhaps the commonest is what could be termed the Nelsonian approach, that is, simply to turn a blind eye to the whole question. b) Also frequent is the oracular method, that is, to declare at the outset that the claimant is a truthful, reliable, straightforward, honest and trustworthy witness, who is not exaggerating. This is presumably based more on telepathy than science, and could in any case be seen as usurping the authority of the court. c) Sometimes, one sees the question dealt with via the DSM and the ICD10; in other words, because the symptoms described fit with what is in the classifications, it is thought to add to the credibility of the account. As we have seen, bearing in mind the cautions inherent in the DSM, it is difficult to regard this as much more than a comfort blanket approach. How Common Are Credibility Problems? There is no definitive medical answer to this, since the ultimate decision on credibility is a legal one. For the legal system to answer the question, it would be necessary to construct a follow-up study of a representative sample of claims entering the legal system, which would be difficult enough in itself. Subsequently establishing what is known in epidemiological terms as caseness, in other words whether or not the claim was found to have credibility problems, would be very difficult, since many cases are presumably finalised without a clear determination of credibility or otherwise, and often after a period of many months at least, if not several years. Such a Herculean research effort would be for the lawyers to initiate, if it were practically possible, though many doctors, including the present author, would be keen to assist if it got started. Hence, whilst the question of the prevalence of credibility problems amongst claims, as definitively determined by the courts, remains thus unanswered, doctors are thus forced to rely on proxy measures to attempt to answer this interesting question. The most widely quoted study on the prevalence of credibility problems in claimants is probably that of Mittenberg, 13 who surveyed practising US neuropsychologists; their opinion was that around 20 to 30% of their cases involved malingering or symptom exaggeration:

13 Base rates of probable malingering or symptom exaggeration (were obtained) from a survey of the American Board of Clinical Neuropsychology membership. Estimates were based on 33,531 (cases) 29% of personal injury, 30% of disability, 19% of criminal, and 8% of medical cases involved probable malingering and symptom exaggeration. 39% of mild head injury, 35% of fibromyalgia/chronic fatigue, 31% of chronic pain, 27% of neurotoxic, and 22% of electrical injury claims resulted in diagnostic impressions of probable malingering Surveys using symptom validity testing and other psychological techniques (described below) indicate that the prevalence of malingering ranges from 25% to almost 50% in compensation seeking neurological and chronic pain patients. 14 In our consecutive series of 119 claimants of injury compensation or sickness benefits, 62% had evidence of exaggeration. 15 Symptom Validity Testing Symptom validity testing essentially involves listing or quantifying the claimant s symptoms, and comparing the results with those from standard groups to see if the claimed symptoms are reasonable. This is not the place for a detailed description, but I will attempt briefly to cover the principles. Two types of symptom validity testing can broadly be distinguished. Physical. The best known test of this type is grip strength on the Smedley dynamometer, where the claimant s grip strength can be compared with normative values for age, sex, etc. This is not currently routinely done by psychiatrists or psychologists. A very low score compared with control data could presumably tend, in the absence of physical disease causes, to indicate poor effort. 16 Psychological. Here the claimant s performance on standard testing or on specially designed tests is evaluated. By standard testing is meant measures of intelligence, for example the WAIS, or of personality, for example the MMPI. The claimant s results are compared with what would be expected given age, gender, educational level etc. So that for example if a claimant who was doing a professional job before the litigated event is given such testing, and scores at a level indicating very low intelligence, there would be some concern about whether he has responded fairly on the testing, absent a brain injury or other cause for the low scores. This type of testing is almost exclusively within the remit of the psychologist. Specially designed tests either seek to evaluate whether the claimant is making a good effort on tests of intellectual performance (so-called effort tests, which appear to have become the best developed type of symptom validity tests, and will be discussed below in a separate section) or look at whether he may be over reporting symptoms. In the latter approach, the claimant is given a checklist of plausible and implausible symptoms; his responses can be compared with normative values; over endorsement of unlikely symptoms can be suggestive of exaggeration. An example of such a test is the MFAST. This can be useful in assessment of possible malingered psychosis, which occurs in forensic (i.e. criminal) psychiatry, though this is rare in civil litigation. The reader is referred elsewhere for further discussion. 17 Cognitive Symptom Validity Testing Cognitive effort testing will now be discussed further. For convenience, it will be referred to henceforward as effort testing. It comes from the field of neuropsychology. This is the specialised branch of psychology developed by psychologists working with patients with brain injuries. Over the years, techniques, now well established, have been developed for the quantitative assessment of intellectual function. Scores are reduced, as would be expected, following major brain injury, for example in patients who have been unconscious for a long time, with fractured skulls, bleeding inside the brain, abnormal brain scans etc.

14 Scores in mild head injury (where the patient has not been unconscious or only briefly unconscious) are, as would be expected, usually normal or only slightly reduced. But there is a problem: some patients score as low as patients who have had an undoubted physical injury to the brain or even lower. The dilemma is: are these scores genuinely low? or is the patient, for whatever reason, making a poor effort on the test? Effort testing has developed in order to try to measure the effort that patients bring to the performance of neuropsychological tests. The principle is that patients are given a test of memory or concentration, which looks difficult, but is in fact known to be easy from previous administration to control subjects. The principle of it is not new. For example, the phenomenon of approximate answers (e.g. Question: How many legs has a horse? Answer: three) was described in the 19 th century by Ganser as a feature of prisoners apparently feigning confusion to avoid criminal law proceedings or conscription. Here, the subject has been given an easy question, to which everyone knows the correct answer, so his nearly right but wrong answer is therefore likely deliberate, implying that the confusion he displays may be feigned. But this is crude; a subject of any sophistication intent on deceit would presumably be unlikely to answer anything other than four, for fear of being found out, and this test would therefore, if used medico-legally, which it rarely is, generate a false negative in such a subject. Regarding quantitative tests of memory, someone making a good effort: scores well on tests which are in fact easy (even though they may look hard); scores lower on more difficult tests Someone making an inconsistent or poor effort: may score low on tests which look hard (though they are in fact easy); may not score lower on more difficult tests.

15 The first graph (Figure 1) shows the results of a claimant on four different memory tests, easy on the left, and then gradually increasing in difficulty, so that the most difficult with one is on the right. We can see that the claimant s scores increase as the test becomes more difficult. This pattern of results tends to indicate that the claimant may not have made a full effort on the test.

16 If we then add in (Figure 2) comparison data from children aged seven showing a near 100% response on the same tests, then the claimant s effort on testing is further brought into question. If scores indicate an inconsistent effort of this kind, but the patient says at the end of testing that they actually made a full effort, then this indicates that their self-report of the effort they put into the test is probably inaccurate. This would be consistent with exaggeration of symptoms of intellectual difficulty, and by extension, of other types of symptom as well. Widely used effort tests include the Test of Memory Malingering, known as the TOMM, 18 a test of pictorial memory, and the Word Memory Test. 19 Acceptance of Effort Testing In the US, symptom validity testing is now seen as essential in neuropsychology practice. 20 It has become accepted in the UK also, at least in head injury claims, though matters are at an earlier stage in respect of other types of case. Interpretation of Effort Test Failure It is very important not to overinterpret failure on symptom validity testing. Ultimately, it is just one piece of information amongst others. It needs to be interpreted in the light of the overall clinical picture. In particular, it is important to realise that effort testing is not in any way a litmus test or lie detector. It must, in short, not be thought of as tending to usurp the authority of the court in determining the credibility of the claimant. Properly regarded, effort testing is just one technique amongst others. It may help the court by more clearly identifying the possibility of exaggeration. Ultimately however the significance of exaggeration, some degree of which may presumably be expected in an adversarial system, must be decided by the court. Conclusions The courts seem to require psychiatric injury to be diagnosed according to official psychiatric classifications such as the DSM and the ICD, but these classifications were designed for research and clinical purposes, not legal use. Conceptual issues thus arise if the classifications are used in the law; their inbuilt checks and balances should not be ignored though they often are. Research indicates that symptoms and disability are common in the population, and many claimants will have experienced before the litigated event the symptoms that they attribute to it. The role of trauma has been overestimated in the genesis of post traumatic stress disorder; one of the chief architects of the concept has in January 2008 written in the British Journal of Psychiatry that traumatic events as defined are neither necessary nor sufficient to produce it. Exaggeration of symptoms is common amongst claimants. New psychological techniques can help to identify it, but must not be overinterpreted. References 1. DSM-IV-TR: Diagnostic and Statistical Manual of Mental Disorders, American Psychiatric Association, See 3. See 4. See 5. A Horwitz and J Wakefield, The Loss of Sadness (New York: OUP, 2007). 6. Turner et al, Selective publication of antidepressant trials and its influence on apparent efficacy, N Engl J Med Jan 17;358(3):

17 7. Kessler et al, Posttraumatic stress disorder in the National Comorbidity Survey. Arch Gen Psychiatry Dec;52(12): Breslau et al, Trauma and posttraumatic stress disorder in the community: the 1996 Detroit Area Survey of Trauma. Arch Gen Psychiatry Jul;55(7): GM Rosen et al, Problems with the post-traumatic stress disorder diagnosis and its future in DSM V, Br J Psychiatry Jan;192(1): C Ihlebaek et al, Prevalence of subjective health complaints (SHC) in Norway. Scand J Public Health. 2002;30(1): K Kroenke, AD Mangelsdorff, Common symptoms in ambulatory care: incidence, evaluation, therapy, and outcome. Am J Med Mar; 86(3): F Wolfe, For example is not evidence: fibromyalgia and the law [Editorial]. J Rheumatol. 2000;27: W Mittenberg et al, Base rates of malingering and symptom exaggeration. J Clin Exp Neuropsychol Dec;24(8): KW Greve, et al, Detecting malingering in traumatic brain injury and chronic pain: a comparison of three forced-choice symptom validity tests, Clin Neuropsychol Sep; 22(5): D Gill, et al, The role of effort testing in independent medical examinations. Med Leg J 2007; 75 (Pt 2): MF Greiffenstein, WJ Baker & T Gola (1996). Motor dysfunction profiles in traumatic brain injury and postconcussion syndrome, Journal of the International Neuropsychology Society, 2, RL Jackson et al, Forensic applications of the Miller Forensic Assessment of Symptoms Test (MFAST): screening for feigned disorders in competency to stand trial evaluations. Law Hum Behav Apr; 29(2): TN Tombaugh. The Test of Memory Malingering, Psychological Assessment, 9, See SS Bush et al, Symptom validity assessment: practice issues and medical necessity, NAN policy & planning committee. Arch Clin Neuropsychol Jun;20(4):