Taken together, the present findings and previous literature suggest that DD may represent a core neurocognitive dysfunction contributing to a range of problem behaviors characterized by reduced sensitivity to the delayed consequences of one’s decisions and actions. The preference for immediate but smaller rewards may be a behavioral marker of underlying genetic liability to impaired decision making and could serve as a useful endophenotype for genetic studies of the etiology of substance use disorders. The finding of genetic influences on this behavioral phenotype raises the question about genetic influences on specific neural substrates underlying intertemporal choices. These issues need to be addressed in future studies using cognitive brain electrophysiology and/or functional neuroimaging methods in genetically informative designs.
