reliability over short periods of time (W. G. Iacono & Lykken, 1981), and be present when clinical symptoms are inactive or during disorder remission (W. G. Iacono, Peloquin, Lumry, Valentine, & Tuason, 1982; e.g., W. G. Iacono, Tuason, & Johnson, 1981). An ideal endophenotype would be immune to the consequences of treatment; otherwise, it would not be possible to identify whether the genetic liability is present in treated individuals. However, if the hope that endophenotypes contribute to understanding etiologic mechanisms is realized and treatments that target the mechanism are developed, it is possible that treatment success could be indexed through the modification of the neurobehavioral trait.
