It is well known that in some small European countries there exist especially favourable conditions for certain types of research which elsewhere meet enormous difficulties. This is exemplified in Denmark and other Scandinavian countries by the famous studies on the influence of genetic and environmental factors in schizophrenia, which were made possible by the exceptional availability of well organized national registers on twins, adoptees and psychotics.

The concept of mental illness which Henry Maudsley developed and espoused has a special significance at this time. Psychiatry appears to have entered a new phase in its evolution as a mental science, in which its dependence on both the biological and the psychosocial disciplines is recognized, in which clinical observations are made under carefully controlled conditions, and where hypotheses lead to research rather than conclusions. This maturation was encouraged and predicted by Henry Maudsley who, more than a century earlier, had synthesized from the knowledge of his time a prospectus of psychiatric progress which anticipates much of our present thinking, often in considerable detail and striking exactitude.

In research into the origin of schizophrenia discrepancies repeatedly arise through the habit of treating schizophrenia as an entity. If independent subforms are differentiated, many ambiguities can be cleared up. A special form of catatonia (periodic catatonia) seems to be transmitted by dominant inheritance, a special paraphrenia (affective paraphrenia) recessively. In a large group of schizophrenias (systematic schizophrenias) with a poor outcome family histories of psychosis were rarely found, but examination of twins suggested a psychosocial origin for the disorder. In cycloid psychoses with a benign outcome family histories of psychosis were also seldom found. Only by diagnostic separations can the discrepancies in the field of schizophrenia be solved.

Four channels of EEG (T4-T6, P4-02, T3-T5, P3-01) were recorded from several groups of control subjects and schizophrenia patients on analogue tape. They were later digitized and analysed by computer; power spectra were computed for 30 second epochs of EEG per channel; eyes closed, eyes open. No difference between normal controls and neurotic in-patients was apparent. An acute schizophrenic group had less alpha power, this change being confined largely to the temporal areas. A chronic outpatient sample showed less alpha and beta power, while chronic long-stay schizophrenic patients had an excess of delta power. The changes in both chronic patient groups were diffuse rather than local.

This 18 month prospective study assessed the time course of sleep disturbances in 85 male psychiatric out-patients and 103 male non-patients. Over one-third of the patients and 5 per cent of the non-patients reported frequent symptoms of insomnia during at least 14 of the 18 months. Frequency and chronicity of insomnia were strongly associated with intensity of psychiatric symptomatology, but not with diagnosis. Minor tranquillizers and hypnotics were used frequently by patients and occasionally by non-patients, but there was little indication that they altered the course of insomnia.

The patients discharged from a 24 bed acute psychiatric admission ward over a six-month period after the introduction of a contract admission procedure were compared with a similar group, discharged over the identical six-month period of the preceding year, before the use of the new procedure. The length of stay in hospital was found to be reduced, but preliminary studies suggest that the re-admission rate is not significantly altered. There was no evidence to suggest that shortening the length of stay in hospital increased the likelihood of relapse, nor were increased demands made on the day hospital service.

The work histories of 75 completed suicides and 150 controls were compared to test Durkheim's theory of the protective nature of work. The suicides showed more unemployment, more absence through illness, had more frequent job changes and held their jobs for shorter periods. They were less likely to retire gradually. There was no difference in social class mobility. Suicides were more likely to come from high risk occupations. The comparatively poor work record of the suicides is attributed to their high level of psychiatric morbidity.

Six of eleven drug-free schizophrenic patients who were depressed following remission of their illness showed a significant decrease in their depressive symptomatology during a double-blind, placebo substitution lithium trial. Traditional indicators of prognosis did not predict lithium response in this small sample; the schizophrenic patients tolerated the lithium well. Lithium should be studied further in a larger patient sample as an adjunct in the treatment of post-psychotic depression, which frequently is treatment resistant.

Psychological and somatic symptoms presented by women in middle life are frequently attributed to the menopause. Many writers have questioned this assumption and have placed more emphasis on environmental and personality factors. Using a life event model and a multivariate analysis technique, life stress was shown to have a significantly more powerful influence on the elevation of symptoms in a normal population of women at that age than did the menopause. Furthermore, the elevation in symptoms occurred some considerable time before that event. The finding that there was no significant increase in total life stress at that time of life suggests the presence of a vulnerability or moderating factor.

The duration of standardised overbreathing required to produce slow wave activity in the EEG during different phases of the menstrual cycle has been studied, and changes in carbon dioxide sensitivity of the respiratory system. Normal subjects developed slow waves more quickly and had more sensitive CO2 responses during the premenstrual/menstrual phases. This may be a factor contributing to premenstrual tension.

Plasma Cortisol, free and total tryptophan were determined in 71 subjects on 8 occasions between 36 weeks gestation and 6 weeks post-partum. Affect was measured by rating scales and clinical interview. Twenty-eight subjects were judged to have experienced post-partum ‘blues'. Seasonal variation occurred in the incidence of ‘blues' and in Cortisol and free tryptophan levels. Puerperally-depressed mood was correlated with high Cortisol at 38 weeks irrespective of season. Free tryptophan was reduced in ‘blues' subjects but only at the time of year when free tryptophan was normally high. Total tryptophan was low antenatally; a rapid rise on days 1 and 2 post-partum was superimposed on a slower return to normal. This initial peak was clearly absent in 37 per cent of subjects. Its absence was significantly related to occurrence of post-partum ‘blues' and of complaints of depression in the ensuing 6 months. This finding is discussed in relation to the possible occurrence of an occult disturbance of tryptophan handling in subjects susceptible to depression.