The Effects of a Working Memory Load on Delay Discounting in Those With Externalizing Psychopathology

This study investigated the influence of executive working memory (EWM) capacity on impulsive decision making in a sample of young adults (N = 623) who varied in degree of externalizing psychopathology (EXT) by examining (a) the effects of WM load on delay discounting rates and (b) the association between EWM capacity and delay discounting rates. EXT was measured as a latent variable indicated by lifetime problems with alcohol, marijuana, nicotine, other drugs, childhood conduct, and adult antisocial behavior. Results showed that (a) the WM load increased discounting rates throughout the spectrum of EXT, (b) EXT was associated with higher discounting rates and lower EWM capacity, and (c) EWM capacity was significantly associated with higher discounting rates when controlling for IQ, but only after a WM load. The results are discussed in terms of the role of EWM capacity in impulsive decision making in EXT.