Neuromodulation for treatment-resistant depression: Functional network targets contributing to antidepressive...

Area of Science:

• Neuroscience
• Psychiatry
• Medical Engineering

Background:

• Treatment-resistant depression (TRD) presents a significant clinical challenge, with current therapies often lacking predictable efficacy.
• Both non-invasive (e.g., transcranial magnetic stimulation, TMS) and invasive (e.g., deep brain stimulation, DBS) neuromodulation techniques are employed for TRD.
• Understanding the precise neural circuits targeted by these therapies is crucial for optimizing treatment selection.

Purpose of the Study:

• To review therapeutic approaches for TRD, focusing on neuromodulation modalities.
• To elucidate the functional networks modulated by TMS and DBS in TRD patients.
• To hypothesize that both invasive and non-invasive neuromodulation impact shared neural networks.

Main Methods:

• Review of clinical studies utilizing functional imaging and tractography in TRD patients.
• Analysis of mechanisms of action for non-invasive and intracranial stimulation.
• Examination of factors differentiating responders from non-responders to neuromodulation.

Main Results:

• TMS targets cortical regions like the dorsolateral prefrontal cortex (DLPFC), influencing interconnected mood and cognition networks.
• DBS targeting deeper structures like the subcallosal cingulate cortex (SCC) engages emotion regulation and reward pathways.
• Evidence suggests overlap in the neural networks modulated by different stimulation modalities.

Conclusions:

• Neuromodulation approaches for TRD, including TMS and DBS, likely act on shared critical neural nodes.
• Personalized, connectome-guided target identification can inform a stepwise neuromodulation paradigm for TRD.
• Developing a theoretical basis for intervention selection can lead to more predictable and targeted psychiatric treatment.