Changes in hierarchical brain dynamics of rumination following mindfulness-based cognitive therapy for depression

In people with major depressive disorder, mindfulness-based cognitive therapy (MBCT) plus treatment as usual, compared to treatment as usual alone, increased the hierarchical organization of brain activity during rumination but not at rest. Greater hierarchy—meaning more directional information flow and less recurrent looping—was linked to improvements in clinical and behavioral outcomes. This shift away from self-reinforcing negative mental loops toward more differentiated cognitive and bodily cycles may help explain how MBCT interrupts ruminative thought patterns. Hierarchical brain dynamics could serve as a treatment-sensitive marker and potential mechanism of therapeutic change in MBCT for depression.

Study at a glance

Abstract

Abstract Major depressive disorder (MDD) is a leading cause of disability worldwide with risk of onset and recurrence linked to depressive ruminative thought patterns. Mindfulness-based cognitive therapy (MBCT) is an evidence-based treatment for depression that targets the ability to recognise, decenter, and disengage from ruminative thought patterns. Elucidating how MBCT impacts hierarchical brain organisation may be key to understanding the processes by which MBCT can modulate ruminative tendencies. In a randomised controlled functional magnetic resonance imaging (fMRI) trial on individuals with MDD (N=80) before and after MBCT in addition to treatment as usual (TAU), we investigated changes in hierarchical brain organisation during resting-state and rumination. We built whole-brain models to obtain generative connectivity (GEC) matrices per patient and quantified brain hierarchy by measuring the global directedness and regional trophic levels in each GEC, in which greater directedness reflects more directional information flow and less recurrence. Global directedness in MBCT+TAU compared to TAU increased during rumination, with no changes during resting-state. Furthermore, increased regional breadth of hierarchy during rumination was related to improvements in clinical and behavioural outcomes following MBCT+TAU. Increased brain hierarchy during rumination following mindfulness training may be consistent with a shift away from self-reinforcing negative mental loops towards more differentiated and less coupled cognitive and bodily cycles, supporting MBCT’s ability to interrupt ruminative processes. Hierarchical brain dynamics may hold promise as a treatment-sensitive marker and a potential mechanism of therapeutic change in MBCT for depression. Trial registration ClinicalTrials.gov NCT03353493 .