AUTHOR=Tadayonnejad Reza , Majid DS-Adnan , Tsolaki Evangelia , Rane Riddhi , Wang Huan , Moody Teena D. , Pauli Wolfgang M. , Pouratian Nader , Bari Ausaf A. , Murray Stuart B. , O'Doherty John P. , Feusner Jamie D. 

TITLE=Mesolimbic Neurobehavioral Mechanisms of Reward Motivation in Anorexia Nervosa: A Multimodal Imaging Study

JOURNAL=Frontiers in Psychiatry

VOLUME=Volume 13 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/psychiatry/articles/10.3389/fpsyt.2022.806327

DOI=10.3389/fpsyt.2022.806327

ISSN=1664-0640

ABSTRACT=Diminished motivation to pursue and obtain primary and secondary rewards has been demonstrated in anorexia nervosa (AN). However, the neurobehavioral mechanisms underlying the behavioral activation component of aberrant reward motivation remains incompletely understood. This work aims to explore this underexplored facet of reward motivation in AN.
We recruited female adolescents with AN, restricting type (n=32) and a healthy control group (n=28). All participants underwent functional magnetic resonance imaging (fMRI) while performing a monetary reward task. Diffusion MRI data was also collected to examine the reward motivation circuit’s structural connectivity. Behavioral results demonstrated slower speed of reward-seeking behavior in those with AN compared with controls. Accompanying this was lower functional connectivity and reduced white matter structural integrity of the connection between the ventral tegmental area/substantia nigra pars compacta and the nucleus accumbens within the mesolimbic circuit. Further, there was evidence of neurobehavioral decoupling in AN between reward-seeking behavior and mesolimbic regional activation and functional connectivity. Aberrant activity of the bed nucleus of the stria terminalis (BNST) and its connectivity with the mesolimbic system was also evident in AN during the reward motivation period. Our findings suggest functional and structural dysconnectivity within a mesolimbic reward circuit, neurofunctional decoupling from reward-seeking behavior, and abnormal BNST function and circuit interaction with the mesolimbic system. These results reveal underlying neurobiological mechanisms of an aberrant behavioral activation component of reward motivation in AN. The findings have implications for potential neurobehavioral targets for novel brain-based treatments of abnormal reward motivation in AN.