TABLE 1.

Neuromodulatory approaches including putative endovascular ones for treatment resistant major depressive disorder.

Neuromodulatory approach	Advantages	Disadvantages	Targets
DBS	-Permanent, continuous treatment -Precise and accurate targeting	Invasive implantation	Subgenual Cingulate Gyrus, Nucleus Accumbens, Anterior limb of Internal Capsule (Volkmann and Deuschl, 2007)
TMS	Non-invasive, short duration, and low-intensity stimulus	Variable efficacy and results, lack of a standardized protocol, treatment to be delivered by non-home-based equipment.	Multiple, commonly Dorsolateral Prefrontal cortex (Berlim et al., 2017)
VNS	FDA approved for treatment resistant depression	Incision needed to implant pulse generator. Unclear efficacy	Vagus nerve (Rush et al., 2000)
Endovascular Stimulation	Minimally invasive, access deep structures	-Antiplatelet Therapy	-Nucleus Accumbens (ACA, 2.2-2.6mm) (Aldaoud et al., 2018)
		-Limited Targeting	-Subgenual cingulate white matter (A2 ACA, 1.9-2.2mm) (Aldaoud et al., 2018)
		-Unclear long-term safety	-Vagus nerve (internal jugular vein)
			-Dorsolateral Prefrontal Cortex (middle meningeal artery)

DBS, deep brain stimulation; TMS, transcranial magnetic stimulation; VNS, vagal nerve stimulation; ACA, anterior cerebral artery.