CAUSES AND CONSEQUENCES OF THE GENDER DIFFERENCE IN AGE AT ONSET OF SCHIZOPHRENIA

The ABC (age, beginning, course) schizophrenia study was commenced in 1987 to generate and test hypotheses about pathogenic aspects of schiz ophrenia, One of the main branches of the study focused on how gender influences the age distribution of onset, symptomatology, illness beha vior, and early course in schizophrenia, Proceeding from one of the ra re, strikingly deviating, consistent findings-the gender difference in age at first admission-we launched a systematic search for explanatio ns by generating and testing hypotheses in a series of substudies. We moved from the epidemiological to the neurobiological and finally to t he clinical level, The present article is an attempt to provide a brie f overview of the individual stages of the ABC study and the different levels of investigation involved in formulating and testing the estro gen hypothesis in animal experiments and in demonstrating its applicab ility to human schizophrenia. From these results, three hypotheses wer e formulated and tested on data from an ABC study sample of 232 first- episode cases of schizophrenia, The analyses described here represent the latest stages of the ABC study.