We examined the hypothesis that changes in the suicide rate of England and Wales since 1900 are an artefact of changes in the process of classifying violent deaths. Four potential sources of artefact were considered: (1) the reliability of the procedure for investigating suspected suicides; (2) coding by the Office of Population Censuses and Surveys; (3) changes in the law; (4) High Court decisions on suicide. None of these can explain the large observed fluctuations in the suicide rate.

Concepts of disease have often been influenced by mediaeval scholasticdoctrines. Today these are best replaced by the premises of modern class logic. One of the basic problems then concerns the universal class of patients. Its solution depends on the answer to the question: What are the distinguishing attributes of this class? Scadding stipulated that these attributes must differ from the norm of a species and be associated with biological disadvantage. This paper argues that these attributes must be abnormal by the standards of a population and/or the norms of an individual, and must be associated with at least one of three criteria: (a) therapeutic concern for himself experienced by a person, (b) such concern for him experienced by his social environment, and (c) medical concern for him. This solution, though based on subjective criteria, seems to tally with the actual practice in diagnosing disease.

I am grateful for the opportunity to comment on Dr Kräupl Taylor's paper. I agree with much of what he says and think that he agrees with some of what I have said. We both disapprove of Platonic realism, for which the term ‘essentialism’ used by Popper (1945) seems to me preferable, since it avoids the danger of confusion with the very different meaning of ‘realism’ in the later idealism–realism opposition. But he has misunderstood my position in the nominalist-essentialist argument; and he seems to think that my statement about the meaning of the names of diseases in medical discourse and the application of ‘modern systems of class logic’ in medicine are in some way incompatible or discordant, whereas I think they are complementary to each other.

The age-specific lifetime prevalence rate of a disease is the proportion of persons surviving to a given age who have experienced the disease at any time during their lives. This measure of morbidity has been used to report findings in many of the epidemiological surveys of mental disorders of the last 30 years. This paper presents a life-table method for estimating age-specific lifetime prevalence rates from incidence and mortality data. The method is applied to Monroe County, New York, case register data on the incidence of schizophrenia. Using this method, we estimate that at least 3% of the White population surviving to age 55 have experienced an episode of schizophrenia at some time during their lives. The difficulties of producing valid estimates of lifetime prevalence and the difficulties in interpreting differences reported in such rates make this morbidity measure of secondary importance to incidence and point-prevalence data.

A survey was made of studies reporting population prevalence rates for the different types of neurotic disorders in order to determine the utility of these rates for familial and genetic research. Rates varied considerably among studies both for all neuroses and for particular types of neuroses, even among studies using similar methods examining similar populations. The method of case ascertainment (personal interview versus record searches) and the threshold for defining an individual as affected are important contributors to variation. The use of the published prevalence rates for quantifying familial and genetic effects on the neurotic disorders would be premature.

The diagnoses were reviewed of 866 women interviewed in 5 community surveys carried out by the Bedford College team. The diagnoses matched commonly held conceptions of who is a case in terms of both severity and type of syndrome. Two methods of replicating the diagnoses are presented, one based on discriminant function analysis and the other based on a simple checklist.

Principal component analysis was applied to data relating to depressive experiences collected from a general population sample. The structure of depression found in the general population showed strong similarities to that found in the psychiatric population. There were, however, important differences. Four substantial syndromes of depression were identified: ‘anxiety depression’, ‘cognitive depression’, ‘vegetative depression’ and depression characterized by the classic endogenous triad of diurnal variations, early wakening, and weight loss. These syndromes were essentially independent for this sample. Examination of component score distributions suggested that people simultaneously experience differing degrees of each syndrome. It was concluded that depression was most parsimoniously classified in dimensional rather than categorical terms within this sample.

In-patient data show high rates for mental illness in the Republic of Ireland, particularly for schizophrenia. ‘One-day prevalence’ figures from the Three County psychiatric case register have been compared with similar data from the Camberwell register. The results confirm much higher contact rates in Ireland.

Nineteenth-century theory held that mental disorder was rare in stable, traditional rural societies. Today most societies are rapidly changing, but Tonga still fits that model and the evidence suggests that the psychoses are genuinely infrequent there. It is proposed that both the theory and the evidence deserve further examination.

The assessments of deliberate self-poisoning patients carried out by 8 doctors and 8 nurses were compared. Both groups of staff had undergone special training in the assessment procedure. The adequacy of the assessments was determined by blind judges' ratings of transcripts of assessment interviews, comparisons of the types of treatment offered and repetition of self-poisoning. The attitudes of the patients and their general practitioners were also investigated.

No major differences were found between the assessments of the 2 groups of subjects. It is concluded that nurses under supervision of a senior psychiatrist can safely carry out the assessment of self-poisoning patients, provided they have received appropriate training. The findings suggest that services in which nurses assess most self-poisoning patients could be established in district general hospitals. This would reduce the demands currently placed on psychiatrists and physicians.

This study compares the clinical and social outcome for 2 cohorts of patients who had a first admission for schizophrenia 4 years earlier. One cohort was treated in a psychiatric unit attached to a teaching district general hospital (DGH(T)), while the other was treated at an area mental hospital (AMH) with modern rehabilitation facilities. The clinical outcome for the 2 cohorts was broadly similar, but the DGH(T) imposed less of a strain on relatives, and was associated with less unmet need. The DGH unit tended to have significantly shorter durations of stay for its patients, so that its total hospital costs were less than those for the AMH despite higher unit costs. The cost benefit analysis shows that, where these particular patients are concerned, the DGH(T) unit is economically superior to the AMH despite the fact that it supports a large teaching staff, and that these economic advantages are accompanied by various non-monetary advantages.

This report concerns a group of schizophrenics whose visual evoked potential reduced in amplitude most markedly in A5 (averaged potential evoked by 1 Hz flashes which started 5 min after the addition test for 15 min). These patients in general had poor productive symptoms and progressed very slowly. Most of them were simple schizophrenics.

A reliable method for recording the site and duration of purposeless movements was devised. With this method 267 subjects were studied, 182 of whom had been exposed to neuroleptics. The results were submitted to a principal components analysis and 3 movement dimensions emerged. One group of movements resembled a parkinsonian syndrome. The other 2 groups of movements both conformed to the generally accepted criteria for tardive dyskinesia. These groups were: (1) head and neck movements and (2) trunk and limb movements. The possibility of the second and third groups representing clinically relevant sub-syndromes of tardive dyskinesia is discussed.

Erythrocyte Na–K ATPase and sodium pump site numbers were estimated in groups of depressed, manic and recovered patients. The activity of Na–K ATPase per pump site was lower in the depressed group than in the recovered group. In the manic group Na–K ATPase was lower than that of the recovered group, whereas there was no difference in the pump site numbers. In the more severe manics the activity of Na–K ATPase per pump site was significantly lower than that of the recovered patients. Therefore, the change occurring in the erythrocyte membrane cation carrier in manic-depressive psychosis is probably in the activity of individual Na–K ATPase molecules and not in the number of Na–K ATPase molecules per cell.

The functional organization of chemically transmitting synapses in the brain are described with special emphasis on recent studies demonstrating the localization of different transmitters to specific anatomical circuitries. The use of pharmacological tools for manipulating levels of chemical transmitters is referred to briefly, but particular attention is given to the problems of studying the function of these pathways with lesion techniques.

Noradrenaline (NA) and dopamine (DA) are selected for detailed consideration and experimental evidence reviewed, suggesting that these two catecholamines in the forebrain serve different functions: NA with processes of attention essential for learning, and DA with the execution of appropriate responses. Hypotheses suggesting dysfunction of forebrain DA and NA systems in schizophrenia are discussed.

The rate of recovery of the H-reflex, an electrical evoked monosynaptic spinal cord reflex, was abnormally high (fast) in over 20% of unmedicated psychotic patients of all major diagnostic classes. A few patients had significantly lower H-reflex recovery curves. Chronic neuroleptic treatment produced relatively lower recovery curves, whereas fluoxetine, a specific serotonin uptake blocker, produced relatively higher curves.

The extent to which the second member of a pair of monotic clicks facilitates simple reaction time was examined for 35 psychiatric patients and 43 non-patient controls across 2 studies. Affective psychotic patients showed greater reaction time facilitation than did either schizophrenic patients or non-patient controls. Computer simulations of a ‘statistical facilitation’ model for these data are also presented.

The relationship between herpes simplex virus type 1 and mental retardation is explored by studying the antibody levels to this virus in a group of 86 severely and profoundly retarded adults. A tendency towards higher antibody levels is found in patients whose retardation is of unknown aetiology. The relationship of these observations to previous research findings and the possible significance of herpes simplex virus in the aetiology of mental retardation are discussed