Excessive discounting of delayed reinforcers as a trans-disease process: Update on the state of the science

Abstract

Delay discounting, or the process by which reinforcers lose value with delay to their receipt, has been identified as a trans-disease process underlying addiction, other disorders, and maladaptive health behaviors. Delay discounting has been identified as an endophenotype for multiple psychiatric disorders including substance use disorder, ADHD, and major depressive disorder, with this endophenotype being linked to deficits in dopaminergic and serotonergic neurotransmission. In addition, neuroanatomical and neurophysiological deficits in areas of the executive and impulsive systems have been associated with both steeper discounting and substance use disorders. Delay discounting constitutes a novel target for interventions to change health behaviors. A new theory, termed reinforcer pathology, has been developed uniting these findings and setting the stage for future research.

Figure 1.

Schematic representation of delay discounting (DD) as a trans-disease process. Genetic, neural, environmental and other factors can increase DD rates and therefore modulate the risk of substance use disorder (e.g., AUD), other disorders (e.g., obesity and schizophrenia) as well as a maladaptive health behavior (e.g., poor medication adherence and texting while driving). Importantly, many of the risks modulated by DD (e.g., AUD, and obesity) have the capacity to feed-back and increase the steepness of DD rates. DD’s ability to predict engagement in multiple health behaviors has been shown not only across individuals, but more recently, within individuals as well. Promising novel interventions (e.g., TMS and EFT) are now targeting DD as a means to positively affect associated disorders and behaviors.