A series of studies in schizophrenia, using several varieties of the twin study method, are reviewed and five major conclusions or hypotheses drawn. A modified twin study design—the co-twin comparison method—is described, with which these conclusions and hypotheses can be tested; and two additional major issues—specificity to schizophrenia, and the antecedent-consequent question—dealt with. A stress model of schizophrenia pathogenesis is presented, which attempts to integrate genetic, biochemical, and experiential variables.
Pollin W. The Pathogenesis of SchizophreniaPossible Relationships Between Genetic, Biochemical, and Experiential Factors. Arch Gen Psychiatry. 1972;27(1):29-37. doi:10.1001/archpsyc.1972.01750250021002