In a study of children adopted at an early age, discrimination between hereditary and family dynamic factors is possible. The biological parents have given the child their genetic characteristics and sometimes the very early environment, while the adoptive parents have provided the more permanent family environment and rearing. The major goal of the Finnish adoptive family study was to re-assess the genetic contributions to schizophrenia and to provide further measures of the adoptive family rearing environment. In other words, we were interested in the joint effects of genetic and family environmental variables and in their possible contribution to both the psychopathology and the healthy functioning of adoptees during their development. This approach paid attention to the possibility that a healthy, possibly protective, rearing family environment may reduce the genetic risk. During the course of the study, we also considered whether the direction of the effects between genetic and family environmental factors can be clarified through a prospective, longitudinal study of the adoptees at risk.
Genetic and Psychosocial Factors in Schizophrenia: The Finnish Adoptive Family Study