title: Multi-dimensional modulations of α and γ cortical dynamics following mindfulness-based cognitive therapy in Major Depressive Disorder.
abstract: To illuminate candidate neural working mechanisms of Mindfulness-Based Cognitive Therapy (MBCT) in the treatment of recurrent depressive disorder, parallel to the potential interplays between modulations in electro-cortical dynamics and depressive symptom severity and self-compassionate experience. Linear and nonlinear α and γ EEG oscillatory dynamics were examined concomitant to an affective Go/NoGo paradigm, pre-to-post MBCT or natural wait-list, in 51 recurrent depressive patients. Specific EEG variables investigated were; (1) induced event-related (de-) synchronisation (ERD/ERS), (2) evoked power, and (3) inter-/intra-hemispheric coherence. Secondary clinical measures included depressive severity and experiences of self-compassion. MBCT significantly downregulated α and γ power, reflecting increased cortical excitability. Enhanced α-desynchronisation/ERD was observed for negative material opposed to attenuated α-ERD towards positively valenced stimuli, suggesting activation of neural networks usually hypoactive in depression, related to positive emotion regulation. MBCT-related increase in left-intra-hemispheric α-coherence of the fronto-parietal circuit aligned with these synchronisation dynamics. Ameliorated depressive severity and increased self-compassionate experience pre-to-post MBCT correlated with α-ERD change. The multi-dimensional neural mechanisms of MBCT pertain to task-specific linear and non-linear neural synchronisation and connectivity network dynamics. We propose MBCT-related modulations in differing cortical oscillatory bands have discrete excitatory (enacting positive emotionality) and inhibitory (disengaging from negative material) effects, where mediation in the α and γ bands relates to the former.
authors.affiliation: Intelligent Systems, Faculty of Science, Radboud University Nijmegen, Postbus 9010, 6500GL Nijmegen, The Netherlands ; Department of Cognitive Neuroscience, Radboud University Medical Centre, Nijmegen, The Netherlands ; Department of Psychiatry, Radboud University Medical Centre, Nijmegen, The Netherlands ; Netherlands Institute for Advanced Study, Wassenaar, The Netherlands.
authors.forename: Poppy L A
authors.initials: PL
authors.lastname: Schoenberg
authors.affiliation: Department of Psychiatry, Radboud University Medical Centre, Nijmegen, The Netherlands.
authors.forename: Anne E M
authors.initials: AE
authors.lastname: Speckens
keywords: EEG power; ERD/ERS; Major Depressive Disorder (MDD); Mindfulness-Based Cognitive Therapy (MBCT); Oscillatory EEG; α-Band coherence; γ-Band