Regulation of Craving: Stress-challenge and re-exposure effects

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Stress and craving are important predictors for relapse in patients with substance use disorders. Prior work has shown that patients can reduce self-reported craving by imagining the long-term negative consequences of using when confronted with substance cues (e.g. images of people smoking). Neurally, this was associated with activity of the prefrontal cortex and it was shown that activity of areas such as the ventral striatum and amygdala, which are closely linked with craving, were reduced.The aim of the first study is to examine the influence of stress on the capacity to regulate craving for cigarettes and its neural substrates (using functional magnetic resonance imaging; fMRI) in heavy smokers. Male heavy smokers are randomly assigned to a stress induction (socially evaluated cold pressor task) or control condition and perform a regulation of craving task involving a smoking and food (control) condition during a fMRI scan. Saliva samples will be taken at several time points and we assume that stress-induced effects of catecholamines and glucocorticoids interfere with prefrontally mediated control mechanisms and thus impair regulatory success (at the behavioral and neural level). Further, we will evaluate whether the level of executive functioning predicts maintained regulatory capacity in the face of stress. The aim of the second study of this proposal is to compare the prospective effects of strategies to regulate craving and its electrophysiological correlates using the electroencephalogram (EEG). Here, the late positive potential (LPP) will serve as a robust marker of attention for substance cues and their potential to elicit craving. During a single EEG session, heavy smokers perform a regulation of craving task, which involves imagination of the long-term negative consequences of smoking and distraction through solving arithmetic problems. After a short break, participants will be re-exposed to the previously presented substance cues, without instructions to regulate craving. We assume that strategies involving elaboration of a substance cue are more successful on the long run than strategies to reduce craving by mere distraction. Smokers should be able to rapidly reduce craving and the LPP amplitude associated with smoking cues through both strategies. However, upon re-exposure, smokers should report more craving and higher LPP amplitudes in response to smoking cues previously subject to distraction relative to smoking cues previously subject to imagining the long-term negative consequences of smoking.Since regulation strategies are frequently successful in the laboratory but much more difficult to implement in real life, this project will improve our understanding of factors facilitating or impairing regulatory success and how they interact. Furthermore, the EEG study will facilitate understanding and characterization of “rebound effects” associated with some regulation strategies and their effects on craving and cue-exposure.