Effects of simulated and real opioid withdrawal on delay discounting for opioids and money in people who use fentanyl daily.

Delay discounting describes the devaluation of consequences as the delay to their occurrence increases, which can yield a preference for smaller, sooner over larger, later rewards. Conceptual models and preliminary data suggest that delay discounting is exacerbated in deprivation states, including opioid withdrawal, which can shift choice allocation to more immediate rewards. Although withdrawal is hypothesized to affect decision making in opioid use disorder, research that experimentally manipulates withdrawal in people with opioid use disorder is limited by feasibility considerations. Simulated withdrawal manipulations could address this gap, but their validity is not well established. The current analysis compared the effects of real and simulated opioid withdrawal on delay discounting in people with moderate-to-severe opioid use disorder and daily fentanyl use by combining data from two previous studies. Study 1 (n = 12) elicited opioid withdrawal via double-blind, placebo substitution of oxycodone maintenance medication during inpatient admission. Study 2 (n = 17) simulated opioid withdrawal via verbal instructions to outpatient participants. All participants completed five-trial, adjusting delay discounting tasks for money and opioid pills. Linear mixed models revealed steeper rates of discounting of delayed opioid pills during opioid withdrawal, regardless of withdrawal manipulation modality (real or simulated). Delay discounting for money was steeper in the simulated withdrawal group only, potentially reflecting pre-existing group differences in the sensitivity of money discounting during withdrawal. These results are consistent with prior research and support the use of simulated withdrawal as an effective experimental proxy in decision-making studies when real withdrawal manipulations are not feasible or warranted. (PsycInfo Database Record (c) 2026 APA, all rights reserved).