Mindfulness-based cognitive therapy is associated with distinct resting-state neural patterns in patients with generalized anxiety disorder.

Abstract

Mindfulness-based cognitive therapy (MBCT) may be effective for generalized anxiety disorder (GAD); however, the neural mechanism is poorly understood. In this study, we examined the potential neural mechanisms through which MBCT may reduce anxiety in patients with mild-to-moderate GAD. Eight weekly group MBCT sessions (2 h each) were conducted with 32 GAD patients. Resting-state functional magnetic resonance imaging (fMRI) was used, along with clinical and mindfulness profiles. A regional homogeneity (ReHo) approach was applied, and resting-state functional connectivity in the default mode network (DMN) using the posterior cingulate cortex (PCC) seed was examined. MBCT reduced the anxiety and increased the mindfulness abilities of patients. After MBCT, patients had reduced ReHo in broad regions of the limbic system, along with increased DMN functional connectivity in the anterior cingulate cortex (ACC) and bilateral insula. Overlapping regions of reduced ReHo and increased DMN functional connectivity were observed in the mid-cingulate cortex (MCC) and bilateral insula. The increased PCC-ACC and PCC-insula functional connectivity following MBCT were related to anxiety improvements, suggesting a potential therapeutic mechanism for mindfulness-based therapies. Group MBCT treatment appears to have effectively reduced anxiety symptoms in patients with mild-to-moderate GAD. Activation and functional connectivity appeared significantly different across some limbic regions after MBCT treatment. The salience network showed reduced ReHo and increased connectivity to the PCC. The DMN functional connectivity of the MCC may indicate reduced anxiety and improved mindfulness in GAD patients.