Intrinsic Brain Network Biomarkers of Antidepressant Response: a Review

Abstract

Purpose of review: Poor treatment response is a hallmark of major depressive disorder. To tackle this problem, recent neuroimaging studies have sought to characterize antidepressant response in terms of pretreatment differences in intrinsic functional brain networks. Our aim is to review recent studies that predict antidepressant response using intrinsic network connectivity. We discuss current methodological limitations and directions for future antidepressant biomarker studies.

Recent findings: Functional connectivity stemming from the subgenual and rostral anterior cingulate has shown particular consistency in predicting antidepressant response. Differences in this connectivity may prove fruitful in differentiating treatment responders to many antidepressant interventions. Future biomarker studies should integrate biological MDD subtypes to address the disorder's inherent clinical heterogeneity. These clinical and scientific advancements have the potential to address this population marked by limited treatment response. Methodological considerations, including patient selection, response criteria, and model overfitting, will require future investigation to ensure that biomarkers generalize for prospective prediction of treatment response.

Keywords: Biomarker; Brain networks; Major depressive disorder; Network connectivity; Predictor; Treatment response.

Fig. 1

Intrinsic brain networks may be used to differentiate depressed treatment responders from nonresponders. a The four intrinsic brain networks implicated in MDD (default mode = yellow, salience = blue, central executive = red, and ventromedial reward = green). Networks were generated using [23]. b Connectivity changes commonly reproduced in depressed patients compared to healthy controls (adapted from [24]). Red boxes and lines indicate increased within-network and between-network connectivity, respectively. Blue boxes and lines indicate decreased within-network and between-network connectivity, respectively. c Nodes and connectivity implicated in predicting antidepressant treatment response, colored by intrinsic brain network membership