Overall design and methodology of the Israeli high-risk study.

The unique contribution of the Israeli high-risk study is the comparison of children at risk for schizophrenia with matched controls in two settings: those raised in nuclear families in towns, and those raised in children's houses on kibbutzim. Such a design makes possible direct comparison of genetic and environmental effects on the psychosocial functioning of a group of high-risk children, over time. In this article we describe methods of collecting and examining the sample, provide an overview of the examination procedures, and describe the basic principles of data analysis.