Does acute stress influence the Pavlovian-to-instrumental transfer effect? Implications for substance use disorders

Sabine Steins-Loeber,Theodora Duka,Frank Lörsch,Caroline Van Der Velde,Oliver T Wolf,Astrid Müller,Matthias Brand

doi:10.1007/s00213-020-05534-8

Abstract

RationalThe ability of conditioned stimuli to affect instrumental responding is a robust finding from animal as well as human research and is assumed as a key factor regarding the development and maintenance of addictive behaviour.ObjectivesWhile it is well known that stress is an important factor for relapse after treatment, little is known about the impact of stress on conditioned substance-associated stimuli and their influence on instrumental responding.MethodsWe administered in the present study a Pavlovian-to-instrumental transfer (PIT) paradigm with stimuli associated with smoking- and chocolate-related rewards using points in a token economy to light to moderate smokers who also indicated to like eating chocolate. After completion of the first two phases of the PIT paradigm (i.e. Pavlovian training and instrumental trainings), participants were randomly allocated to the socially evaluated cold pressor test or a control condition before the final phase of the PIT paradigm, the transfer phase, was administered.ResultsThe presentation of a smoking-related stimulus enhanced instrumental responding for a smoking-related reward (i.e. ‘smoking-PIT’ effect) and presentation of a chocolate-related stimulus for a chocolate-related reward (i.e. ‘chocolate-PIT’ effect) in participants aware of the experimental contingencies as indicated by expectancy ratings. However, acute stress did not change (i.e. neither enhanced nor attenuated) the ‘smoking-PIT’ effect or the ‘chocolate-PIT’ effect, and no overall effect of acute stress on tobacco choice was observed in aware participants.ConclusionsThe established role of stress in addiction appears not to be driven by an augmenting effect on the ability of drug stimuli to promote drug-seeking.

Highlights

Substance use disorders are a major health problem
While it is well known that stress is an important factor for the development and maintenance of substance use disorder (Koob 2008; Schwabe et al 2011), little is known about the potential interplay of stress with learning processes and instrumental behaviour
In the transfer phase, the presentation of the stimulus related to smoking (CSS) increased responding for a smoking-related reward (i.e. ‘smoking Pavlovian-to-instrumental transfer (PIT)’ effect), while the presentation of a stimulus related to chocolate (CSC) increased responding for a chocolate-related reward (i.e. ‘chocolate PIT’ effect)

Summary

Introduction

Substance use disorders are a major health problem. While a large number of individuals suffering from a substance use disorder quit substance use without therapeutic interventions (Heyman 2013), there are individuals who show a chronic course of the disease. Some authors propose that stress can disrupt top-down inhibitory control of the dorsolateral prefrontal cortex (Woodcock et al 2019), promote a transfer to habit behaviour (Schwabe et al 2011) or enhance stimulus-triggered ‘wanting’ (but not necessarily ‘liking’) of the reward through raising dopamine levels in the nucleus accumbens (Sinha 2001; Hyman et al 2006; Graf et al 2013) Another pathway may be that stress increases the expected value of a drug driving goaldirected drug choice (Mathew et al 2017; Shuai et al 2020; Hogarth et al 2019a; Hogarth and Hardy 2018; Hogarth et al 2015a)

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