Onset and course of the first schizophrenic episode.

Schizophrenia seems to occur with equal frequency in all countries and cultures. The ecological and social disparity of prevalence rates in open societies is not due to social causes, but to selection processes. At what point in the course of the disease social disadvantage begins and on account of which mechanisms is a question of both theoretical and practical importance. In a representative sample of 232 first episodes the true onset of schizophrenia is assessed by means of a standardized interview (IRAOS). The onset is 3 to 4 years later in women than in men, which is a result of the protective effect of estrogens as confirmed by animal experiments and by a controlled clinical study. For women the distribution of disease onset across the entire age range shows a delayed increase in adolescence and a second peak in the age group 40-45, presumably due to the fading effect of estrogen around menopause. For three quarters of all schizophrenias the onset lies between 15 and 30 years of age, the period of steepest social development. The distribution of the social biography through the psychosis, which occurs on average 3-4 years earlier in males than in females, determines the social starting conditions of the disorder and affects the early social course. Nearly 75% of the total cases begin with a prodromal phase of 5 years on average. The psychotic prephase lasts 1.1 years. The mainly negative prodromal symptoms are often associated with social and cognitive deficits already at this stage. In a case control study social stagnation or decline occur already during the prodromal phase. After the end of the first episode the mean values of social disability and the objective social status remain fairly stable over a period of at least three years. So far treatment and rehabilitation measures are not started until after first admission, which means after several years' duration of the disease when the majority of social deficits have already become manifest.