The personality of patients with myalgic encephalomyelitis.

ABSTRACT

The aim of this study was to replicate earlier research by McEvedy and Beard, using a group of people with a clear diagnosis of Myalgic Encephalomyelitis (M.E.). Their scores on the EPI were compared to those recorded by a non-symptomatic control group as well as a group of patients suffering from another chronic illness (M.S. group).

The results suggest that the slightly raised Neuroticism scores of people with M.S. do not necessarily indicate a hysterical personality or neuroticism. Both the limitations of the EPI as a measure of Neuroticism and Extraversion in people with physical illnesses and the psycho-social sequelae of conditions such as M.E. may have affected the responses on the inventory. These factors should also be considered when interpreting the data obtained by McEvedy and Beard. Consequently, it was impossible to draw any firm conclusions about the role of personality in the aetiology of M.E.

INTRODUCTION

Myalgic Encephalomyelitis (M.E.) is a condition characterised by profound fatigue, muscle weakness and a general malaise. It occurs both sporadically and in epidemic form¹. As a result of a repeated failure to identify an aetiological agent and the consistently negative laboratory findings, this illness has been regarded by many doctors as a psychoso­matic complaint when it occurs sporadically and as mass hysteria when it occurs in epidemics.

One of the most frequently cited examples of a M.E. epidemic is the outbreak at the Royal Free Hospital in North London in 1955². This affected 292 members of staff including 149 nurses and caused the temporary closure of the hospital. In 1970, two psychiatrists, McEvedy and Beard³ reassessed the available information on the epidemic and argued that since the vast majority of those affected had been young women who were socially segregated, and as no organic cause had been found, the outbreak could be regarded as an example of mass hysteria.

In 1973, they published the results of a follow-up study of some of the nurses who had been ill during the 1955 outbreak⁴. These showed that the mean Neuroticism score on the Eysenck Personality Inventory (EPI)⁵ of 71 affected nurses was significantly higher than that of a control group of unaffected nurses. Since hysterics are assumed to have higher than normal Neuroticism scores, they considered their data to be supportive for their mass hysteria hypothesis.

The aim of the following study was to replicate McEvedy and Beard’s research, using people with clear diagnosis of Myalgic Encephalomyelitis.

METHOD

Members of the M.E. Association were asked via the Newsletter and via group meetings in London and Surrey to participate in a study to investigate the personality of M.E. sufferers. It was stipulated that those willing to fill in a questionnaire should not be on psychotropic drugs and that they should have been diagnosed by a physician, preferably on the basis of laboratory tests indicating a persistent viral infection.

Volunteers were sent two copies of Form B of the EPI and a background questionnaire, to obtain such information as their age, gender, their symptoms and the duration of their illness. They were instructed to fill in one copy of Form B and to ask a member of their family, a neighbour or a close friend who lived in the same area and. who did not suffer from a chronic illness, to act as a non-symptomatic control by filling in the second copy.

At the same time, people suffering from Multiple sclerosis (M.S.) were approached via the ARMS Newsletter and asked to fill in the same form and so act as a second control group.

RESULTS

Unfortunately, the majority of M.E. sufferers are still diag­nosed on clinical history alone, and it was therefore very dif­ficult to find suitable subjects. The following are the re­sults of the first 40 people who returned their questionnaires.

The commonest symptoms were fatigue, muscle weakness and muscle pain, followed by headache, dizziness and flu-like symptoms. Some sufferers reported having recurrent sore throats, cold extremities and balance problems and a few mentioned sleep disturbances, depression, mood changes and difficulty in concentration. Of those who responded, just over half were feeling ill or very ill at the time; the others were feeling relatively well. None had completely recovered.

Details about age, sex and duration of illness can be found in Table 1.

Table 1

  * Information not complete.

Only a minority were being treated with orthodox drugs, but of these, the commonest were Nystatin and analgesics.

NEUROTICISM

As Table 2 shows, the mean Neuroticism score of the M.E. group was found to be only a little higher than that of the non-symptomatic control group and that of the normal population reported by Eysenck and Eysenck⁵. In fact, it was very close to that recorded by the ‘affected’ nurses who were assessed by McEvedy and Beard. However, it was lower than that of the M.S. group and also well below those recorded by an­xious people (16.5), hysterics (15.77) and a mixed neurotic population (14.9)⁵.

When the positive scores on 6 items enquiring about typical M.E. symptoms (e.g. tiredness, dizziness and headaches) were removed from the analysis, it made very little difference to the scores of the non-symptomatic control group. In contrast, the corrected, mean of the M.E. sufferers was well below the uncorrected mean (Wilcoxon test for related samples p<0.01), as was the corrected mean of the M.S. group.

Finally, the mean neuroticism score of 12 subjects whose ill­ness had lasted less than 5 years was compared with that of 8 subjects whose illness had lasted at least 10 years. The score of the former was found to be 1O.83, that of the latter was 14.75. Surprisingly, this difference was not statistically significant.

EXTRAVERSION

As indicated in Table 2, the mean Extraversion score of the M.E. group was lower than that of the non-symptomatic control group and well below those of the general population and the subjects assessed by McEvedy and Beard in their study. It was also found to be lower than the mean scores recorded by hysterical people (12.80) and a mixed neurotic population (12.16) but it is interesting to note that it was higher than the score of the M.S group.

The mean L (Lie) scores for all groups was low.

DISCUSSION

The mean Neuroticism score of the M.E. sufferers in this study was 12, which is very similar to the score of 12.2 recorded by the nurses who had been ill during the outbreak of encephalomyelitis at the Royal Free Hospital in 1955. However, there are several reasons why this finding does not necessarily support McEvedy and Beard’s contention that their subjects may have had personalities rendering them susceptible to hysteria.

First of all, measuring Neuroticism in physically ill subjects using the EPI is difficult because there are at least 6 items which ask about symptoms commonly experienced by people with M.E. and M.S. For example, item 16 asks ‘have you often felt listless and tired for no good reason’ and item 35 enquires ‘Do you have dizzy turns?’

This problem has already been noted in relation to Multiple Sclerosis and the MMPI ^6,7. For example, Marsh et al wrote “applying MMPI interpretations based on a psychiatric population without deleting test items relating to the neurological disorder results in spurious profiles and inaccurate interpretations. The need for correction scores is especially relevant for multiple sclerosis, a chronic neuro­logical disorder characterised by many somatic symptoms that have been mistaken for hysterical or psychophysiological re­actions”.

M.E. sufferers too, may give positive responses on certain items on the basis of their ill health, rather than their emotional over-sensitivity. It was therefore decided, after consultation with several physicians, to ‘correct’ the scores by omitting 6 of the items, in order to ascertain whether the mean of the group changed significantly. Of course, this procedure violates the assumptions on which the scale was constructed, but it was nevertheless thought to be useful as a means of comparison within this study. Moreover, it was hoped that it would give a more accurate indication of the emotional over-sensitivity of M.E. sufferers.

The results showed that the corrected mean of the M.E. group was only slightly higher than that of the non-symptomatic control group, suggesting that the Neuroticism scores obtained by McEvedy and Beard may have been raised because of the inadequacies of the EPI alone.

Another factor which should be taken into account when in­terpreting the data is the possible influence of the psycho­social sequelae of disease on personality and responses on personality inventories. The raised Neuroticism scores of the M.S. group and of the M.E. group who had been ill for more than 10 years may reflect, in part, the strain of chronic illness and disability. The tendency towards lower Extraversion scores in both patient groups is also consistent with this view.

It is known that illnesses such as M.E. and M.S. often place restraints on sufferers, as a result of which they cannot be as outgoing, lively and carefree as they were prior to the illness. In this society, friends and relatives, fearful of their own emotions, tend to stay away from those who are chronically and/or terminally ill, leaving the patient feeling rejected, isolated and lonely⁸. Altered financial circumstances, bad housing and dependence on others impose further limitations on the lives of many disabled people and the effects of factors such as these should not be underestimated. However, as the difference between the Extraversion scores of the M.E. group and the non-symptomatic controls was so small, it is not possi­ble at this stage, to draw any firm conclusions.

In order to get a clearer idea of the relationship between M.E. and personality, I included a question on the background questionnaire, enquiring whether the subjects themselves thought that their illness had affected their personality. A few respondents wrote that they could not answer that question as they had been ill since childhood. The vast majority who answered the question however, replied in the affirmative. Some believed that they were more irritable, snappy, moody and liable to overreact to trivial problems than before; one person mentioned that the illness had sapped her self-confidence and that it had made her more pessimistic. Another wrote that he seemed to have become more introvert. On the other hand, several reported that the illness had made them more stoical, more philosophical, more compassionate, less ambitious and more content with “little things”.

In addition to the limitations associated with the use of the EPI, the responses recorded by the nurses in McEvedy and Beard’s study may also have been coloured by the continued ill health of some of the subjects. Although it cannot be assumed that all of the nurses in that study had actually suffered from encephalomyelitis (about a hundred were in fact thought to have had other conditions¹), McEvedy and Beard did not check that all those who had been ill, had indeed recovered. A follow-up study of patients involved in the epi­demic at Akureyri, Iceland in 1948-1949⁹ showed that many of them were still experiencing residual signs and symptoms six years later. Preliminary data from a similar study into the health of the Royal Free Hospital patients have also indicated that a substantial number of them have some residual symptoms¹⁰.

Thus it is possible that some of the nurses in McEvedy and Beard’s study were still suffering from symptoms which originated during the epidemic in 1955. Consequently, it is not inconceivable that their raised Neuroticism scores could have reflected some of the psycho-social, physiological and biochemical effects of M.E.^1,8.

Unfortunately, as a result of the methodological limitations of this study, one can do little more than speculate. Personality factors may have played a part in the aetiology of M.E. in some of the sufferers, and this deserves further study, particularly in the light of recent research in the field of psycho-immunology. However, the findings of this study do not support the view that M.E. sufferers as a whole, are more ‘neurotic’ than ‘normal’ people.

ACKNOWLEDGEMENTS

I would like to thank the ME Association and all those who participated in this study.

REFERENCES

1.          Ramsay AM. Postviral Fatigue Syndrome. The Saga of the Royal Free Disease. London: Gower Medical Publications, 1986.

2.       The Medical Staff of the Royal Free Hospital. An attack of Encephalomyelitis in the Royal Free Hospital group, London, in 1955. Br Med J 1957; 2: 895-904.

3.          McEvedy CP and Beard AW. Royal Free epidemic of 1955: a reconsideration. Br Med J 1970; 1: 7-111.

4.          McEvedy CP and Beard AW. A controlled follow-up of cases involved in an epidemic of ‘Benign Myalgic Encephalomyelitis’. Br J Psychiat 1973; 122: 141-150.

5.          Eysenck HJ and Eysenck SBG. Eysenck Personality Inventory. Sevenoaks: Hodder and Stoughton, 1964.

6.       Marsh GG, Hirsh SH and Leung G. Use and misuse of the MMPI in Multiple Sclerosis. Psychol Reports 1982; 51: 1127-1134.

7.          Baldwin MV. A clinico-experimental investigation into the psychologic aspects of Multiple Sclerosis. J Nerv Ment Dis 1952; 115: 299-342.

8.          Hartnell L. Personal View. Br Med J 1987; 1: 1029.

9.          Sigurdsson B and. Gudmundson KR. Clinical findings six years after the outbreak of Akureyri disease. Lancet 1956; 1: 766-767.

10.          Ramsay AM. Presentation at the Annual General Meeting of the M.E. Association. April 1988. London.

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