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.

SYNOPSISFrom 1 January 1984 until 30 June 1986 all 517 compulsorily admitted psychiatric patients of a well-defined mixed rural–urban catchment area in Baden-Württemberg, a southern State of the German Federal Republic, were compared with all 10232 voluntarily admitted patients. Because of the very low frequency of compulsory admissions this population can be regarded as a ‘core group’ of committed patients. In a logit analysis the characteristics distinguishing involuntary from voluntary patients can be reduced to three main factors: the diagnosis ‘schizophrenia/ paranoid disorder’, ‘masculine gender’ and the compound indicator ‘not owning a home’, the latter being mainly associated with youth, masculine gender and low occupational status. The strong association of these characteristics with the criteria ‘severity of disease’ and ‘danger to oneself and others’, both pre-requisites for compulsory admission according to the laws of most countries, is discussed.

Sex differences in schizophrenic diseases have been known for a long time but have also been subject to long-term neglect by psychiatric epidemiological research, although a study of these sex differences could, in our opinion, yield valuable pointers to pathogenic factors involved in this group of diseases the aetiology of which still awaits clarification. For this reason we initiated large-scale investigations focussed on this topic. The paper presented here discusses a few initial results, basing on data of Mannheim and National Danish Case Records and on our own study on schizophrenia, the latter being a representative record of 392 patients hospitalised for the first time in the Rhine-Neckar region and the eastern part of the Palatinate. First of all, sex differences at the age at which the disease appeared for the first time, were studied while paying close attention to artifacts and other, usually neglected methodical error sources. The difference in the average age of the sexes at first hospitalisation was confirmed, and also--using an instrument specially developed for that purpose--at the onset of the disease. At the time the first signs of the disease are noticed and the first schizophrenic symptoms become apparent, men are about 3 to 4 years younger than women. On the other hand, the cumulative lifetime risk--calculated up to 60 years of age--seems to be the same for both sexes. It appears that there are no sex differences in the pattern of symptoms of the disease at the time of initial hospital admittance, in respect of both the most common and the characteristic signs and symptoms. There were significant although quantitatively not very great differences in respect of patient behaviour which displays socially positive aspects somewhat more often in women and socially negative ones distinctly more often in men. In respect of the course of the disease we could not find any marked sex differences over a period of 10 years after onset of the disease; however, this is presently based only on the Danish case record data and on criteria of the course of the disease, such as number and duration of inpatient treatments.

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Though replication and further research are needed, the SPro scale may currently be a useful screening tool for initial screening in a two-stage process of early detection of psychopathology.