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SYNOPSISNumerous studies have reported a lower mean age at first hospitalization for schizophrenia in males than in females. For this finding not only a gender difference in age at first onset of schizophrenia, but also other factors can be responsible. With the aim of providing a comprehensive analysis of gender differences in onset, symptomatology and course of schizophrenia, we started by testing the hypothesis postulating a gender difference in mean age at first hospitalization. By using the Danish and the Mannheim psychiatric case registers we analysed all hospital admissions for schizophrenia and related diagnoses and all previous admissions for other diagnoses of the Danish population in 1976 and those of the inhabitants of the German city of Mannheim in the period of 1978–80. Artefacts were controlled for systematically. The impact of intervening variables such as selection factors as well as the influence of gender on the ascription of a diagnosis of schizophrenia for the first time were assessed. We found a mean difference of 5 to 6 years in age at first hospitalization between males and females in both countries when a broad definition of the diagnosis was used and of 4 to 5 years when a restrictive definition was applied. The higher mean age at first hospitalization among females is not attributable to artefacts, diagnostic procedures or to any essential extent to gender differences in help-seeking behaviour or occupational status. When a distinction was made between ‘single’ and ‘married’, the significant difference in age at first hospitalization between the sexes disappeared in singles. With case register data and without knowing the chronological order of marriage and onset of the disease, it remains an open question whether this finding can be explained by purely correlative associations between sex, marital status and age of onset or by causal effects.

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This study reports on the findings from a WHO sponsored cross-national investigation of life events and schizophrenia. Data are presented from a series of 386 acutely ill schizophrenic patients selected from nine field research centers located in developing and developed countries (Aarhus, Denmark; Agra, India; Cali, Colombia; Chandigarh, India; Honolulu, USA; Ibadan, Nigeria; Nagasaki, Japan; Prague, Czechoslovakia; Rochester, USA). On a methodological level, the study demonstrates that life event methodologies originating in the developed countries can be adapted for international studies and may be used to collect reasonably reliable and comparable cross-cultural data on psychosocial factors affecting the course of schizophrenic disorders. Substantive findings replicate the results of prior studies which conclude that socioenvironmental stressors may precipitate schizophrenic attacks and such events tend to cluster in the two to three week period immediately preceding illness onset.

SUMMARY Microelectrode recordings of multiunit sympathetic vasoconstrictor activity were made in muscle branches of the peroneal nerve in patients with essential hypertension before and during long-term treatment with the cardioselective beta-adrenergic receptor antagonist metoprolol. Nerve activity was quantified by counting the number of sympathetic bursts in the mean voltage neurogram. Metoprolol treatment lowered blood pressure and heart rate in all subjects. During longterm treatment, nerve activity was reduced both when compared to the level of activity after the first dose of the drug (p < 0.01) and when compared to the control level before treatment (p < 0.05). It is suggested that the reduction of sympathetic vasoconstrictor outflow to muscles contributed to the blood pressure reduction. (Hypertension 6: 557-562, 1984) KEY WORDS • microelectrode recording • blood pressure • beta-adrenergic receptor antagonists D ESPITE widespread use of beta-adrenergic receptor antagonists in the treatment of arterial hypertension, we do not fully understand how they exert their antihypertensive effect. Acute intravenous administration of beta-adrenergic receptor antagonists devoid of intrinsic sympathomimetic activity reduces heart rate and cardiac output, while the blood pressure remains unchanged. Initially the peripheral vascular resistance increases, but with prolonged therapy it decreases and causes the blood pressure to fall, since the cardiac output remains reduced.1 It is believed that the initial increase and the subsequent decrease in peripheral resistance is due to corresponding changes in sympathetic outflow, but no direct experimental evidence is available in humans because of the lack of adequate methods for measuring sympathetic nerve activity.The development of the microneurographic technique 2 now makes possible the direct recording of sympathetic activity in human peripheral nerves. With this technique it has been found that sympathetic outflow to muscles is involved in blood pressure control. The sympathetic impulses are discharged in bursts in synchrony with cardiac rhythm, and their outflow is influenced by both arterial baroreceptors and intrathoracic low-pressure receptors. The activity can be quantified by counting the bursts and, although there are wide interindividual differences, in a given individual the level of sympathetic activity is remarkably constant over many months. 3 In the present study, we used this technique to investigate whether sympathetic outflow to muscles in patients with essential hypertension is influenced by long-term treatment with metoprolol, a cardioselective beta-adrenergic receptor antagonist without intrinsic sympathomimetic activity. The effect of acute intravenous administration of the drug has been presented in a previous report. 4 Methods PatientsEight patients who had been hospitalized for hypertension were recruited for the study, seven men and one woman aged 26 to 51 (mean 40) years. Hypertension was defined according to the World Health Organization (WH...