Brain Connectivity Between Networks Implied in Inhibition and Cue-reactivity in Alcohol Use Disorder

Overview

Research about patients with alcohol use disorder has shown that task-related brain activation patterns as well as resting-state connectivity (measured with functional magnetic resonance imaging) change with clinical parameters such as the extent of craving and duration of abstinence during treatment. These brain activation alterations are related to treatment success. Although an imbalance between increased cue-reactivity and impaired counteracting inhibitory control processes are at the core of most neuropsychological conceptualizations of alcohol use disorder, the direct interaction between these two processes has not yet been investigated. Therefore, the investigators aim to study patients with alcohol use disorder in an ultra-high-field 7 Tesla magnetic resonance imaging scanner to identify fine-grained activation and connectivity patterns. The investigators would like to improve the knowledge of the interplay between the brain networks for inhibition and cue-reactivity, as well as to explore its influence on craving and treatment success. The investigators hypothesize that a more pronounced negative relationship between increased cue-reactivity and reduced inhibitory control processes in the brain is linked to higher craving and worse relapse probability.

Even if an imbalance between enhanced cue-reactivity and impaired opposing control processes is at the center of most neuroscientific conceptualizations of alcohol use disorder (AUD), these two processes are still rarely investigated in direct interaction. Attempting to target both processes in one design, initial studies reported enhanced brain activation in anterior cingulate cortex (ACC) and ventrolateral prefrontal cortex (vlPFC), when control processes had to be carried out in the context of alcohol-related cues, and linked this altered brain activation to relapse risk. Hence, the proposed study will take advantage of the higher spatial resolution and signal-to-noise ratio of a 7 Tesla fMRI scanner to investigate more subtle effects and the involvement of subregions of vlPFC and ACC during alcohol-related inhibition. Of special interest, particularly when it comes to explaining an imbalance between brain systems related to cue-reactivity and inhibitory control, are concurrent measures of functional brain connectivity. Aberrant resting-state functional connectivity in networks involved in reward prediction, motivation, salience attribution and executive control have been reported in AUD. Also, altered task-related connectivity was observed during cue-reactivity as well as during executive control. However, functional connectivity measures during a task combining both aspects are still missing. Therefore, this study examines the mutual interplay between cue-responsive regions and opposing inhibitory control networks. To this aim, task-related functional connectivity are measured in a specifically tailored experimental design allowing for the assessment of effects related to cue-reactivity, inhibition, as well as their interaction. Besides, this study assesses whether possible interaction effects of task-related functional connectivity between cue-reactivity and inhibitory control vary with craving, change with prolonged abstinence or predicts drinking outcome. Taken together, this study will deepen the understanding of the interplay between neuronal networks central to AUD, cue-reactivity and inhibitory control. The (im)balance between these processes is crucial for recently abstinent patients striving to control drinking habits and urges in an environment infused with alcohol-related cues. As such, markers capturing the interaction between these processes are of high conceptual and clinical relevance and might pave the way towards a potential biomarker indicating enhanced relapse risk.