Rate of cross-commodity discounting of substances varies by substance type for individuals in recovery from substance use disorders.

Abstract

The extant literature hints at the existence of substance-specific differences in rates of cross-commodity discounting (CCT). However, direct examinations are currently lacking. The present experiment aimed to replicate previous studies examining CCT of substances and to extend their findings by examining potential substance-specific relationships with discounting. Participants (n = 122) on recovery pathways from substance use disorders indicated the substances they were still actively using and then ranked these substances from most to least preferred. Participants then completed four discounting tasks: (a) money now-money later, (b) money now-drug later, (c) drug now-drug later, and (d) drug now-money later. Monetary and drug amounts were always equated. In these tasks, the drug commodity was always the participant's most preferred except if participants indicated they used multiple substances, in which case they completed additional discounting tasks with their second most preferred substance. Results revealed that discounting rates across substances did not differ significantly in conditions where the same commodity was both the immediate and the delayed option. In contrast, in the drug now-money later condition, we found that rates of discounting varied significantly according to the specific drug commodity. Further, this relationship was inverted in the money now-drug later condition. Overall, results from previous examinations of the CCT of alcohol and stimulants were replicated. In addition, we provide the first direct evidence that rates of CCT may differ across different substances. (PsycInfo Database Record (c) 2025 APA, all rights reserved).