The hidden-zero effect in male individuals with opioid use disorder

ABSTRACT

Background: Explicitly expressing the hidden opportunity cost in intertemporal choice significantly reduces healthy participants’ delay discounting – a phenomenon named the “hidden-zero effect,” which is undetermined in individuals with substance use disorder (SUD).

Objectives: This study aimed to determine whether the hidden-zero effect occurs among individuals with opioid use disorder (OUD) and the degree to which this effect differs between the OUD group and healthy controls.

Methods: In two different experiments, Exp#1) 29 male individuals with OUD (13.5 ± 6.0 months abstinence) and 29 male controls performed an intertemporal choice task (ICT); Exp#2) 28 male individuals with OUD (17.5 ± 5.6 months abstinence) and 27 male controls performed a delay discounting task (DDT). The OUD group was recruited from a mandatory treatment, and controls from WeChat. There were two choice conditions in both two tasks: the hidden-zero (H0) condition (standard), and the explicit-zero (E0) condition (explicitly expressing opportunity cost).

Results: Compared with the H0 condition, all participants’ delay discounting was significantly decreased in the E0 condition (ps < .05, η_p² = 0.254, 0.110). There was no significant difference in the changed degree between these two groups in either experiment (ps > .05). The delay discounting of the OUD group was significantly higher than that of controls only in Experiment 2 (p < .001, η_p² = 0.376).

Conclusion: This study extended the population in which the hidden-zero effect occurs to individuals with OUD. With respect to delay discounting, the hidden-zero effect benefit did not differ in OUD and control participants.

KEYWORDS:

• Hidden-zero effect
• delay discounting
• intertemporal decision making
• substance use disorder
• opioid use disorder

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supplemental data

Supplemental data for this article can be accessed online at https://doi.org/10.1080/00952990.2023.2231619

Correction Statement

This article has been corrected with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This study was supported by the National Natural Science Foundation of China under Grant [31960185].