Left ventrolateral prefrontal cortical activity during reward expectancy predicts mania risk up to one year post scan.

INTRODUCTION

Identification of neural markers associated with risk for manic symptoms is an important challenge for neuropsychiatric research. Previous work has highlighted the association between predisposition for mania/hypomania and elevated reward sensitivity. Elevated activity in the left ventrolateral prefrontal cortex (L vlPFC) during reward expectancy (RE) is associated with measures predictive of risk for manic/hypomanic symptoms. However, no studies have examined this relationship longitudinally. The goal of this study was to identify a neural marker associated with longitudinal risk for manic/hypomanic symptoms.

METHODS

We used a card guessing functional magnetic resonance imaging (fMRI) paradigm to examine RE-related L vlPFC activity. One hundred and three young adults who were either healthy or experiencing psychological distress completed a single baseline fMRI scan and self-report measures of manic/hypomanic symptoms. Self-report measures were repeated up to two follow up visits over one year.

RESULTS

We identified a significant positive relationship between baseline RE-related L vlPFC activity and MOODS Manic Domain scores up to one-year post scan. This relationship was specific to manic symptoms and was not present for MOODS depression-related domains.

LIMITATIONS

This study was not designed to predict conversion to bipolar disorder, but rather the more proximal construct of lifetime risk for mania/hypomania.

CONCLUSIONS

RE-related L vlPFC activity may serve as an important marker of risk for future manic/hypomanic symptoms and may also be a potential target for intervention.