A systematic review and meta-analysis of resting-state fMRI in anxiety disorders: Need for data sharing to move the field forward

Abstract

Anxiety disorders are among the most prevalent psychiatric disorders. Neuroimaging findings remain uncertain, and resting state functional magnetic resonance (rs-fMRI) connectivity is of particular interest since it is a scalable functional imaging modality. Given heterogeneous past findings for rs-fMRI in anxious individuals, we characterize patterns across anxiety disorders by conducting a systematic review and meta-analysis. Studies were included if they contained at the time of scanning both a healthy group and a patient group. Due to insufficient study numbers, the quantitative meta-analysis only included seed-based studies. We performed an activation likelihood estimation (ALE) analysis that compared patients and healthy volunteers. All analyses were corrected for family-wise error with a cluster-level threshold of p < .05. Patients exhibited hypo-connectivity between the amygdala and the medial frontal gyrus, anterior cingulate cortex, and cingulate gyrus. This finding, however, was not robust to potential file-drawer effects. Though limited by strict inclusion criteria, our results highlight the heterogeneous nature of reported findings. This underscores the need for data sharing when attempting to detect reliable patterns of disruption in brain activity across anxiety disorders.

Keywords: Anxiety; FMRI; Meta-analysis; Neuroimaging; Resting-state.

Figure 1:

PRISMA diagram ¹Longitudinal cohort with no baseline results n=1, prospective/ongoing n=2, case studies n=3, machine learning n=4; ²granger causality analysis n=3, independent component analysis n=5, interhemispheric connectivity n = 2

Figure 2:

Amygdala Seed-Based ALE Meta-analysis: healthy > anxious. Results of amygdala seed-based papers. A single cluster emerged in healthy > anxious contrast. Cluster-corrected at p < .05 with 1000 permutations