Dr DAVID C. POSKANZER, Department of Neurology, Harvard Medical School:
SIR,-The articles of Dr. C. P. McEvedy and A. W. Beard (3 January, pp. 7 and 11) are of considerable concern because of the authors' contention that benign myalgic encephalomyelitis (epidemic neuromyesthenia) is a psychosocial phenomenon related to mass hysteria or to altered xnedical perception in the community. Their erroneous conclusions about this illness may impair future investigations of similar outbreaks.
It is apparent that the authors failed to do their homework, and demonstrated a surprising lack of information about the principles of epidemiology and of psychiatry.
Had they reviewed the literature on the subject, they would have discovered that Albrecht, Oliver, and Poskanzerl investigated an outbreak of this illness in New York and pointed out that an easily recognized laboratory abnormality occurs in this illness.
There is a considerable increase in creatinuria and an increase in the creatine/creatinine ratio, suggesting an abnormality of muscle. On recovery from the symptoms the creatinuria disappeared. Drs. McEvedy and Beard also failed to point out that the epidemic curve, in at least one outbreak,2 was consistent with person to person spread, and that radial spread over time was demonstrated from the centre of the community to the more rural areas.
The question of mass hysteria has been considered by the authors of most papers relating to this disease and in each instance has been discarded for a number of reasons- namely,
(1) cases occurring within the same household are varied in their features
(2) separate illnesses appear at random intervals instead of simultaneously;
(3) epidemiologically, the consistency of course and sirnilarity of symptoms despite the variety of people and communities that were affected make hysteria unlikely. The disease is consistent from outbreak to outbreak in different countries, different years and different peoples.
(4) The mental symptoms of depression, emotional lability, impaired memory and difficulty concentrating are consistent with organic disease as compared with the shallowness and indifference of hysteria.
(5) Muscle pain is a striking feature of most outbreaks. It is clear that sporadic cases of this disease cannot be readily identified. It is only in the epidemic form that the distinctive epidemiological features allow haracterization.
Instead of ascribing benign myalgic encephalomyelitis to mass hysteria or psychoneurosis, may I suggest that the authors consider the possibility that all psychoneurosis is residual deficit from epidemic or sporadic cases of benign myalgic encephalomyelitis?-
I am, etc.,
DAVID C. POSKANZER.
Department of Neurology,
Harvard Medical School,
Boston, Mass., U.S.A.
I Albrecht, R. M., Oliver, V. L., and D. C., 7ournal Poskanzer of the American Medical Association, 1964, 187, 904. 2 Poskanzer, D. C., Henderson, D. A., Kunkle, E. C., Kalter, S. S., Clement, W. B., and Bond, J. O., New England 7ournal of Medicine, 1957, 257, 356.