large sample studies needed to identify verified genetic variants associated with psychopathology can be obtained by pooling those with a harmonized measure of psychopathology. In this context, a key value of endophenotypes will not be to identify novel genetic associations, but rather to identify and characterize neural mechanisms associated with verified genetic variants associated with psychopathology and relevant psychological traits (see Figure 3).Use genetic signals to develop new (and better) endophenotypes. Once verified genetic variants associated with psychopathology are identified, research is encouraged to capitalize on what is known about the likely functional significance of the variants to develop new endophenotypes. An implication of this is that, if in 10 years P300 amplitude reduction is still the most widely studied electrophysiological endophenotype for disinhibitory psychopathology and schizophrenia (see Table 5), we will have to conclude that the endophenotype molecular genetic research program has failed.Endophenotypes are of value even if they do not help find genes. They are underappreciated for their likely predictive utility, ability to enhance understanding of brain mechanisms, and potential to inform animal models (see Section III of Table 1).
