Temporal Discounting Impulsivity and Its Association with Conduct Disorder and Irritability

Temporal reward discounting impulsivity (TDI) reflects a propensity to choose smaller immediate rather than larger delayed rewards relative to age/IQ-matched peers. Previous work with adults has linked TDI to an increased risk for antisocial behavior but also psychopathology in general. However, little work has examined TDI in adolescents with conduct disorder (CD), or considered whether TDI might be associated dimensionally with traits associated with antisocial behavior, that is, impulsivity, irritability, and/or callous-unemotional traits. In this study TDI was investigated in a large adolescent group with varying levels of antisocial behavior. Participants consisted of 195 adolescents (67 with CD, 77 in a psychiatric comparison group and 51 typically developing adolescents). Participants performed a temporal discounting task and individual differences were measured through the Connors rating scale for attention-deficit/hyperactivity disorder (impulsivity), Affective Reactivity Index (irritability), and Inventory of Callous-Unemotional traits. The adolescents with CD and those in the psychiatric comparison group showed significantly greater TDI than typically developing adolescents. However, these group differences were abolished when dimensional covariates were included. Irritability was significantly associated with TDI. We conclude that TDI reflects a transdiagnostic form of dysfunction that particularly manifests in adolescents with increased irritability.