INDICATORS OF LIABILITY TO SCHIZOPHRENIA - PERSPECTIVES FROM GENETIC EPIDEMIOLOGY

Research in genetic epidemiology has provided powerful evidence that g enetic factors contribute to the familial transmission of schizophreni a. However, the precise mode of inheritance has not been elucidated, a nd no disease susceptibility locus has been identified. Genetically co mplex illnesses such as schizophrenia can be characterized by multiple intermediate correlated traits or risk factors that likely play impor tant roles in the susceptibility of individuals to developing the illn ess. Such biobehavioral traits potentially associated with liability t o schizophrenia have been carefully studied by experimental psychopath ologists and are discussed in this issue. This article discusses how c orrelated trait data collected from probands and their relatives can c omplement diagnostic assessments and offer promise for greatly enhanci ng the informativeness of pedigrees for genetic analysis and for facil itating replication of linkage findings. The results of analyses of si mulated and real data discussed here suggest that assessment of biobeh avioral traits with the greatest validity and cost-effectiveness shoul d be required in the next generation of linkage and other genetic stud ies in schizophrenia.