Identification of Genes Influencing a Spectrum of Externalizing Psychopathology

Abstract

Alcohol dependence, drug dependence, childhood conduct disorder, and adult antisocial behavior commonly occur in combination. Data from multiple literatures, including twin/family studies and electrophysiological studies, suggest that the overlap of these disorders is largely due to a shared genetic liability that contributes to a spectrum of externalizing psychopathology. These findings suggest that some genes will not be specific to any one externalizing disorder but will predispose individuals broadly to a spectrum of externalizing psychopathology. Here we review evidence for specific, identified genes, GABRA2 and CHRM2, that follow this pattern and confer risk for a spectrum of externalizing disorders. These findings confirm the etiological structure of psychopathology suggested by psychological research and suggest exciting new roles that psychologists can play in understanding the pathways underlying associations between genes and behavior.