Event-related oscillations to affective stimuli: heritability, linkage and relationship to externalizing disorders.

Event-related oscillations (EROs) are heritable electrophysiological measures associated with cognitive activity and have been shown to be particularly informative for the genetic analysis of substance dependence and other psychiatric disorders. In the present study associations between the cortical event-related oscillations (EROs) elicited by affective stimuli, and the diagnosis of ASPD or CD (ASPD/CD) were investigated, and heritability and linkage analyses conducted in 662 individuals residing in an American Indian community. Results from this study found that participants with ASPD/CD showed increased alpha ERO energy in centro-parietal leads in the 0-250 ms time window in response to all three emotional expressions (sad, neutral and happy faces). Participants with ASPD/CD also showed increased alpha ERO energy in centro-parietal leads in the 400-700 ms time window in response to happy and neutral faces. Variance components analysis suggested a significant familial component to each of the described ERO phenotypes. Although a follow-up genome-wide linkage analysis failed to detect significant evidence of genetic linkage for any of these phenotypes, centro-parietal alpha energy in response to happy faces showed suggestive evidence of linkage to chromosome 1p36.31 (LOD = 2.40), in an area found in previous studies to be associated with externalizing phenotypes. Findings from this study suggest greater activation of neural circuits required to perform a facial recognition task in participants with ASPD/CD. The observed increase in alpha ERO energy may represent a heritable endophenotype associated with select externalizing disorders in this population.