摘要
The identification of genes that contribute to the susceptibilities to complex neuropsychiatric disorders such as schizophrenia, major depression and bipolar disorders has not been as successful using conventional genetic approaches as had been hoped. There are several problems associated with the conventional approaches, including the validity of psychiatric diagnosis itself, excluding carriers of relevant genes who cannot be identified in the absence of manifest symptoms, and the heterogeneity
The identification of genes that contribute to the susceptibilities to complex neuropsychiatric disorders such as schizophrenia, major depression and bipolar disorders has not been as successful using conventional genetic approaches as had been hoped. There are several problems associated with the conventional approaches, including the validity of psychiatric diagnosis itself, excluding carriers of relevant genes who cannot be identified in the absence of manifest symptoms, and the heterogeneity of neuropsychiatric disorders, both clinically and etiologically. A new direction that appears encouraging is the identification of neurobiological and neurobehavioural characteristics, hidden from the ＂naked eye＂ associated with these complex neuropsy- chiatric disorders. These characteristics are termed endophenotypes, that may be more closely linked to gene expression in the causal chain from genes to psychiatric diagnosis disorders [1,2]. An endophenotype is a special kind of biomarker, one that is not the consequence of illness and is heritable. It plays an important role for bridging the gap between the microscopic level （e.g., molecular genetics） and the macroscopic level （e.g., clinical symptoms） of neuropsychiatric disorders such as schizophrenia and bipolar disorders [3,4]. The identification of endophenotypes is very crucial to the identification of genes
