who are at either increased or diminished risk for developing an MEB disorder based on phenotypic characteristics, genotype, or other biological markers (such as physiological or brain imaging measures), or who have a history of environmental exposure offers the prospect for applying indicated prevention strategies. The possibility of targeting interventions based on evidence from developmental neuroscience is genuine and valid if the following criteria are met: (1) the evidence for the association between a marker or exposure and a disorder is sufficient to identify children at risk reliably, (2) a sufficiently powerful strategy for preventive intervention is identified that is relevant for the disorder and the risk factors in question, and (3) the magnitude of the risk or protection that the marker or exposure confers is sufficiently large to justify screening for the marker or exposure.
The potential use of individually identified biological information to determine risk raises important ethical concerns (Institute of Medicine, 2006a; Evans, 2007). These concerns frequently arise in the context of acquiring genetic information, and the rapid increase in genetic research related to MEB disorders has coincided with an increase in public interest and also in private-sector endeavors to provide commercially available access to individual genetic information (Couzin, 2008; Hill and Sahhar, 2006). One concern is appropriate interpretation of the available evidence to determine whether the above criteria have been met before a marker is implemented as a basis for determining individual risk. Genetic and other biological markers are often perceived to be more deterministic than other risk factors in their potential to predict future disease (Austin and Honer, 2005; Hill and Sahhar, 2006; Kendler, 2005; Institute of Medicine, 2006a). However, given the complex, multifactorial etiology of MEB disorders, single genetic variants have very limited predictive power. This is also likely to be true for physiological or brain imaging measures that are being studied in relationship to MEB disorders. Clearly and accurately communicating research findings, including both their promise and limitations, to the public, policy makers, practitioners, and researchers in related disciplines is of paramount importance.
If the evidence does support gathering individual genetic and other biological information for research studies, and especially if testing for MEB disorders becomes available outside the research environment as it has for other health conditions, important decisions must be made. These include who determines whether to test an individual, who can gain access to the test results, who counsels the individual about those results, and who can act on the information (Institute of Medicine, 2006a). On the one hand, limiting access to information about individual risk raises concerns about withholding health information. On the other hand, the availability of individualized information leads to concerns about privacy, stigmatization,