What is stress-diathesis model of schizophrenia?

Schizophrenia may ccur as the result of both genetic (nature) and epigenetic (nurture) factors. That is, an individual with multiple genetic risk factors, combined with multiple stressors causing epigenetic changes, may not have sufficient backup mechanisms to compensate for inefficient information processing within a genetically “biased” circuit. The circuit may be unsuccessfully compensated by overactivation, or it may break down and not activate at all. In either case, the abnormal biological endophenotype would be associated with an abnormal behavioral phenotype, and thus with psychiatric symptoms such as hallucinations, delusions, and thought disorder. Such abnormal circuit activation would be potentially detectable with functional brain scanning, and psychiatric symptoms would be manifest on clinical interview.