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Katie Witkiewitz

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3 papers

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YNICL Journal 2021 Journal Article

Age dependent neural correlates of inhibition and control mechanisms in moderate to heavy drinkers

Megan Swartz
Finnigan Burton
Kishore Vakamudi
Kareem Al-Khalil
Katie Witkiewitz
Eric D. Claus

BACKGROUND: Long-term, heavy alcohol consumption has been associated with impairments in control over alcohol use, but whether this extends to other areas of cognitive and behavioral control such as response inhibition remains unclear. Understanding individual differences in the neural correlates of response inhibition will provide further insight into the neurobiology of heavy drinking. The current study investigated response inhibition in a large sample of moderate to heavy drinkers METHODS: One hundred fifty-three individuals completed a stop signal task while undergoing functional magnetic resonance imaging. Multiple regression analyses focused on blood oxygen level-dependent (BOLD) response contrasts of correct inhibition and failed inhibition as dependent variables and included age, sex, and hazardous drinking (as measured by the Alcohol Use Disorders Identification Test (AUDIT)), and their interactions, as independent variables RESULTS: Age was negatively associated with BOLD response in lateral inferior and middle frontal gyri, anterior cingulate cortex, and inferior parietal lobe for both successful inhibition and failed inhibition contrasts. In addition, there was a significant age × AUDIT interaction in the successful inhibition contrast in the left middle frontal gyrus, with significant negative correlations between AUDIT and BOLD response in older participants, and a significant positive correlation between AUDIT and BOLD response in younger participants CONCLUSIONS: Age appears to be a particularly important factor in predicting BOLD response and may be a critical variable to include in future studies of heavy drinking and alcohol use disorder, particularly those that assess cognitive function. Finally, the age × AUDIT interaction observed in the current study may represent evidence for accelerated aging effects of alcohol on cognitive function.

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YNICL Journal 2020 Journal Article

Brain activation and subjective anxiety during an anticipatory anxiety task is related to clinical outcome during prazosin treatment for alcohol use disorder

Claire E. Wilcox
Bryon Adinoff
Joshua Clifford
Josef Ling
Katie Witkiewitz
Andrew R. Mayer
Kylar M. Boggs
Matthew Eck

BACKGROUND: Higher levels of anxiety, negative affect, and impaired emotion regulation are associated with alcohol use disorder (AUD) and contribute to relapse and worse treatment outcomes. Prazosin, while typically used to treat post-traumatic stress disorder (PTSD) and other anxiety disorders, has shown promise for treating AUD. In order to better understand these underlying neural processes in individuals with AUD, our aims in this study were to measure brain activation during an anticipatory anxiety task before treatment to determine whether observed patterns supported previous work. We then aimed to measure the effects of prazosin on patients with AUD and explore whether greater baseline anticipatory anxiety (as measured by subjective and neural measures) predicts better treatment outcomes. METHODS: Thirty-four individuals seeking treatment for AUD participated in a six-week placebo-controlled study of prazosin and underwent an anticipatory anxiety task during fMRI scans at baseline and three weeks. Alcohol use over six weeks was measured. RESULTS: Greater levels of subjective anxiety and deactivation in posterior cingulate cortex (PCC) and ventromedial prefrontal cortex (vmPFC) were observed during high-threat stimuli compared to low-threat stimuli. Compared to placebo, prazosin reduced subjective anxiety to high-threat stimuli but there were no observed significant effects of prazosin on brain activation during the task. However, AUD patients with greater vmPFC deactivation during high threat relative to low threat and patients with low baseline anticipatory anxiety during the task had worse clinical outcomes on prazosin. CONCLUSIONS: Deactivation in PCC and vmPFC to high-threat stimuli replicated previous work and shows promise for further study as a marker for AUD. Although prazosin did not affect brain activation in the regions of interest during the anticipatory anxiety task, subjective levels of anxiety and brain activation in vmPFC predicted treatment outcomes in individuals with AUD undergoing treatment with prazosin, highlighting individuals more likely to benefit from prazosin than others.

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RLDM Conference 2017 Conference Abstract

Sufficient Markov Decision Processes with Alternating Deep Neural Networks

Longshaokan Wang
Eric Laber
Katie Witkiewitz

Advances in mobile computing technologies have made it possible to monitor and apply data- driven interventions across complex systems in real time. Markov decision processes (MDPs) are the pri- mary model for sequential decision problems with a large or indefinite time horizon. Choosing a repre- sentation of the underlying decision process that is both Markov and low-dimensional is non-trivial. We propose a method for constructing a low-dimensional representation of the original decision process for which: 1. the MDP model holds; 2. a decision strategy that maximizes cumulative reward when applied to the low-dimensional representation also maximizes cumulative reward when applied to the original process. We use a deep neural network to define a class of potential process representations and estimate the process of lowest dimension within this class. The method is evaluated using a suite of simulation experiments, and applied to data from a mobile health intervention targeting smoking and heavy episodic drinking among college students.

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