Dynamical repertoire of brain networks in mindfulness cognitive behavioural therapy during rumination: A randomized controlled trial

Mindfulness-based cognitive therapy (MBCT) alters brain network dynamics during depressive rumination in people with recurrent depression. In a randomized trial, 27 patients received MBCT plus treatment as usual, while 21 received treatment as usual alone. Using fMRI, researchers analyzed brain substates during an induced rumination state before and after treatment. MBCT changed the probability of a specific 'Salience-somatomotor' brain substate occurring during rumination, compared to the control group. These dynamic network changes were linked to reduced depressive symptoms after treatment and at three months follow-up, suggesting a candidate brain mechanism for how mindfulness training improves clinical outcomes.

Study at a glance

Abstract

BACKGROUND: Depression is a prevalent and debilitating affective disorder characterised by the dominance and persistence of depressive rumination. Mindfulness-based cognitive therapy (MBCT) is an effective treatment for recurrent depression developed specifically to target rumination and recurrence risk by training metacognitive awareness and adaptive attention, emotion and self-regulation skills. Yet, the underlying mechanisms by which mindfulness training impacts maladaptive depressive rumination is not well understood, and a deeper understanding of its effects on the complex brain dynamics during depressive rumination is needed. METHOD: In a randomised controlled functional magnetic resonance imaging (fMRI) study (N = 80), we used LEiDA (Leading Eigenvector Dynamics Analysis) to determine the key substates during resting state fMRI of an experimentally induced rumination state before and after treatment with MBCT (N = 27) for recurrent depression in addition to treatment as usual (TAU) or TAU alone (N = 21). We determined the probability of occurrence (fractional occupancy) and the duration (lifetime) of underlying substates (phase-locking patterns) before and after treatment for both groups. RESULTS: We found that MBCT training compared with TAU altered the fractional occupancy of a 'Salience-somatomotor' substate during the depressive rumination induction. These dynamic network changes in turn were associated with reduced depressive symptoms after treatment and at three months follow up. CONCLUSION: In a depressive ruminative state, changes in the dynamics of the somatosensory-salience network following mindfulness training was associated with improved clinical outcomes which provides insight into candidate brain mechanisms or markers of treatment response.