This most important subject, which is likely to affect the whole future of psychiatry, has so far made little progress. Enlightened individuals are beginning to show a way, handicapped by existing law and practice. Some of the most important possible developments are not under the control of those with mental hospital experience, and the diversity of approach and training of those who deal with the different aspects of the subject renders co-ordination still more difficult.

Workers in psychiatric genetics are, with some notable exceptions, psychiatrists first and geneticists second. Neither their medical nor their psychiatric training equips them with an appreciation of scientific method, and their narrow specialization prevents them from keeping abreast of advances in the general field of animal genetics. As things are, this is an important source of weakness; for the general geneticist, whose science is in a much more advanced state, has accumulated facts and theories that have an immediate application in our special field. One has therefore to notice comprehensive reviews of the present position in genetics in relation to the theory of evolution which have recently been provided by Dobzhansky (1941) and Huxley (1942). In what follows the work of Huxley has chiefly been drawn upon, and it is intended to provide a brief summary of the most important of these ideas.

Owing to the difficulties of investigating the sensory organization of the nervous system experimentally, for many years experimental neurologists tended to direct their attention rather to the motor mechanisms, for these can easily be studied and recorded objectively. During the last few years, however, research investigations have been more concentrated on the anatomical basis of sensation and, accordingly, this review will be mainly concerned with this aspect.

It is proposed in this review to deal only with those aspects of physiological psychology that have an immediate bearing on the problems of human behaviour. Here again two limitations must preclude consideration of much important work in this field, in that endocrinology and the study of cortical potentials have been relegated to the special articles dealing with this subject.

The history of electro-encephalography contains both triumphs and disappointments. The most profound of the disappointments is the relative failure to elucidate any of the important problems which concern the psychiatrist. It was hoped that some real electro-physiological alteration would be seen in patients whose mental condition suggested something bordering on the organic, but the negative findings even in the most profound mental disorders are almost as striking as if they were positive. Before considering the published work it would be well to review in a few words the nature and significance of electro-encephalographic records.

Biochemical research has continued in spite of the war and considerable advances have been reported during the period under review. While the task of applying this new biochemical knowledge in the field of psychiatry has hardly yet begun, the underlying chemical mechanisms concerned in nervous activity are becoming considerably clearer and a few beginnings in this direction have been made.

A state of vitamin deficiency arises (i) when inadequate amounts of a vitamin (or vitamins) are ingested, (ii) when absorption from the alimentary canal is defective or interfered with, (iii) when storage mechanisms are at fault, e.g. liver disease, and (iv) when the tissue cells themselves are unable to utilize the vitamin (i, 2). With war rationing the first factor is likely to be commoner than heretofore, especially in alcoholics (3), patients maintaining a strict “peptic ulcer diet” over long periods (4), diabetics (2), mothers sacrificing their rations for the family, food faddists, and in people living alone and doing their own cooking (5). Nowadays many exist on a “borderline” diet, in whom any stress such as pregnancy, infection, surgical procedure, fracture, hyperthyroidism, etc., will precipitate a deficiency state; moreover, in chronic gastro-intestinal disorders the available vitamins may be lost or destroyed (6-14).

In recent years our views of the interaction between the nervous system and the ductless glands have been gradually more defined. In the present review, for descriptive reasons the subject has been classified as follows with reference to the main elements of the neuro-hormonal inter-relation: (1) The influence of the nervous system on the pituitary itself and, through the pituitary, on the other ductless glands.

Increased use of mental tests for the study of psychoses and allied disorders is conspicuous in recent psychiatric practice. This increase is most prominent first in the use of Rorschach's ink-blots; second, in the investigation of conceptual thinking with methods originated by Goldstein; third, in the study of psychometric pattern; fourth, in the diagnosis and measurement of intellectual deterioration; fifth, in assessing prognosis and the effects of treatment. It is partially attributable to sharpening of interest, due to the war, in the prediction of break-down under stress, in the stability and social potentialities of border-line groups, and in estimating the effects of head injury. Another factor is that popular modern treatments such as shock therapy and prefrontal leucotomy appear to involve cerebral areas intimately associated with intelligence. The greatest advances, however, have been made by the followers of Rorschach and of Goldstein and their contributions began before these factors arose. Their methods are also much applied in investigations under the fourth and fifth headings. Their influence, too, is discernible in a change now developing in the way of using mental tests. Whereas in most early investigations tests were used quantitatively as instruments for studying how intelligence level affects and is affected by psychosis, the modern tendency is to use tests not as measuring instruments, but as standard interviews or situations in which the quality rather than the level of the subject's behaviour is studied. On the other hand, perhaps it was growing recognition of the unsuitability of most quantitative tests for application to adults, and of the additional difficulties of interpreting results in psychoses, that first induced search for other techniques.

It is concerned with the isolation of clinical entities on a psychological basis, and with the investigation of the aetiological factors and psychological mechanisms that may be responsible for these conditions. There is much division of opinion among psychopathologists on basic principles. Particularly is this so regarding the relative importance attached to innate factors, infantile experiences, early training and psychical trauma in adult life in the causation of mental disorder.

This review is based on neuropathological contributions which have either a direct or indirect relation to mental disease or are of major general interest. Notwithstanding these restrictions the field which had to be covered remains vast, and no claim can be made that the survey of the literature is complete, although it is hoped that it is, to some extent, representative. In order to counteract this defect, recent reviews or comprehensive papers on special problems have been recommended, whenever they were available. They will enable the reader to trace references which for lack of space had to be suppressed. For the same reason of economy, a number of quotations have been made from reviews. This does not mean that the original papers have not been consulted.

New methods of physical treatment introduced during the last decade have revived the general interest in schizophrenia, the “Cinderella of psychiatry” (Ellery, 1941). The fact that schizophrenic symptoms can be influenced by crude physical means such as convulsions, hypoglycaemia or operations on the brain has directed the attention to the bodily disturbances underlying the psychological symptoms. The need for accurate assessment of results of these treatments has also revived the interest in prognosis. Kraepelin, who, in 1896, “by a streak of genius” (Adolf Meyer) unified varied clinical pictures in what he called dementia praecox and considered it a disease entity, never doubted its causation by a brain process of organic nature. Nor did Bleuler, when he tentatively proposed the term “schizophrenias” for approximately the same group of cases in 1911 in which he found a common primary psychological disturbance. Those interested in the meanings of “splitting” as expressed by the term schizophrenia will find a discussion of possible misunderstandings in an article by Lewin (1939).

Most of the papers written on depression during the last five years have been concerned with matters which are dealt with by other contributors in this volume—its genetics, biochemistry, social aspects (including suicide), psychopathology, and treatment by endocrine preparations, electrical convulsions, and prefrontal leucotomy. The remaining papers, here briefly reviewed, are few in number, mainly clinical, and do not record any outstanding advances.

The discussion of any topic is handicapped so long as there are doubts and disagreement as to what is being discussed.

To discuss progress in the psychoneuroses without encroaching on the subjects of psychopathology and psychotherapy may appear like an attempt to play Hamlet without the Prince of Denmark. However, there remain certain aspects of aetiology, nosology, differential diagnosis and treatment which are not included in those subjects. It must clearly be understood that the ground covered by the following discussion is strictly limited owing to the above considerations. Thus, psycho-analytic work on the neuroses is to a great extent a matter of psychopathology and psychotherapy, and can therefore find little place in this chapter.

The present war has occasioned sudden and notable changes in many aspects of medicine. Psychotherapy is no exception. The war has come at a time when this branch of treatment is receiving a greater measure of acceptance by the profession than ever before. And the war has brought with it a challenging demand for shorter treatment and—if it may be—more permanent results. Thirty or forty years ago psychiatry complacently limited itself to environmental and custodial measures. Since then a gradual infiltration has taken place whereby the psychiatrist accepts an active therapeutic commission. Much of this change is due, directly and indirectly, to the work of Freud, which shook into animation both clinical psychiatry and academic psychology. The interdependence of these three departments of mental science has by no means reached completion. Nevertheless, psychotherapy can look back on a growing contribution to psychiatry, initiated to a large extent in the Great War, and now multiplied many times by the demands of totalitarian warfare.

Medicine has lately become conscious of the special problems set by the increase of life expectancy following the hygienic progress of the last half century. General interest has been roused in the modification of diseases when they occur in the middle-aged and elderly, and in the illnesses typical of the later periods of life. From this movement psychiatry has profited in so far as many problems of “geriatrics” prove to be psychological and psychiatric problems. Our knowledge of facts has been confirmed and widened and the contact with general medicine should prove fruitful (Malamud, 1941).

In the past head injuries have been of comparatively little concern to the psychiatrist. As judged from statistics of admission to mental hospitals they are a small problem. Mapother (1937), for example, who took a very broad view of the causal connection found in L.C.C. mental hospitials—3 per thousand in observation wards, 4 per thousand in psychiatric O.P. depts. in general hospitals, 7 per thousand of the admissions attributable to head injuries. The increasing interest that psychiatrists take in head injuries at present is mainly due to the increasing amount of extramural work that they are being called on to do. In general hospital and outpatient practice they are bound to encounter a considerable number of problems connected with head injuries, both in the acute and in the later stages. The psychiatrists and neuro-psychiatrists in the Services have probably had this experience first, but when adequate provision of psychiatric service becomes available in the general hospitals, many cases will come into the orbit of psychiatrists which hitherto have been “disposed of” without much regard for their mental aspect.