Predicting rTMS treatment efficacy in depression based on modular flexibility of functional connectivity

Area of Science:

• Neuroscience
• Psychiatry
• Medical Imaging

Background:

• Major depressive disorder (MDD) is linked to altered brain circuit function, particularly the default mode network (DMN).
• Repetitive transcranial magnetic stimulation (rTMS) is an effective MDD treatment, but its mechanisms and response predictors are unclear.

Purpose of the Study:

• To investigate the impact of rTMS on dynamic functional connectivity in MDD patients.
• To determine if modular flexibility changes predict clinical outcomes in MDD treated with rTMS.

Main Methods:

• Retrospective analysis of 70 MDD patients receiving active or sham rTMS.
• Resting-state fMRI was used to assess dynamic functional connectivity before and after treatment.
• Left dorsal lateral prefrontal cortex (lDLPFC) targeted rTMS, with functional connectivity to the right nucleus accumbens (NAcc) as a seed.

Main Results:

• Active rTMS significantly reduced Hamilton Depression Rating Scale (HAMD) scores compared to sham.
• Treatment increased modular flexibility in the medial prefrontal cortex (MPFC), a DMN hub, correlating with symptom reduction.
• Baseline modular flexibility in DMN nodes predicted post-treatment HAMD scores.

Conclusions:

• rTMS therapy remodels the DMN's dynamic architecture, enhancing neural flexibility.
• Baseline modular flexibility serves as a potential biomarker for personalizing rTMS treatment.
• This study advances a dynamic network model for neuromodulation, emphasizing neural adaptability restoration.