Charlestown,
Massachusetts
02129
Purpose:
This study will evaluate the short term effects of respiratory-gated transcutaneous vagus
nerve stimulation on the regulation of cardiovagal activity, depressive symptomatology and
immune function in subjects with major depression and determine the optimal stimulation
frequency for this population.
Study summary:
This study will compare the acute effects of respiratory-gated transcutaneous vagus nerve
stimulation (tVNS) at different stimulation frequencies and sham stimulation during five
sessions within a 2 week period. Heart rate variability (HRV) point process adaptive
filtering estimation algorithms will be used to evaluate changes in cardiac autonomic
physiology in subjects with major depression in response to tVNS. The effects of tVNS on
cardiovagal regulation will be evaluated at rest and in response to an emotion reactivity
task. Depression rating scales (Beck's Depression Inventory) will be used to evaluate short
term effects of tVNS on depressive symptoms in these subjects. In addition, the study will
evaluate the acute effects of the stimulation on serum levels of pro-inflammatory cytokines.
The stimulation frequency that produces the greatest regulatory effects on depressive
symptoms and physiological variables in this population will be used in a second longitudinal
phase of the study.
Criteria:
Inclusion Criteria:
- Diagnosis of recurrent Major Depressive Disorder with a current active depressive
episode
- Currently not taking psychiatric medications or on a stable therapeutic dose of
psychiatric medication for at least 30 days prior to entering the study
Exclusion Criteria:
- History of cardio-, cerebro-, or peripheral vascular disease, diabetes mellitus,
morbid obesity (BMI > 40 kg/m2), kidney or liver failure, history of unexplained
fainting spells
- Any psychiatric disorder involving a history of psychosis (e.g. schizophrenia, bipolar
disorders, severe personality disorders)
- Any chronic condition affecting movement, speech and/or ability to read or follow
written instructions
- Substance use disorder, either mild, moderate, or severe within the past 12 months
(excludes nicotine)
- History of suicide attempt within the last year or current active suicidal ideation
- History of a clinically defined neurological disorder including, but not limited to:
Any condition likely to be associated with increased intracranial pressure; space
occupying brain lesion; History of cerebrovascular accident; Transient ischemic attack
within two years; Cerebral aneurysm; Dementia; Parkinson's Disease; Huntington's
chorea; or Multiple sclerosis.
- Pregnant or nursing
- Metallic implants or devices contraindicating tVNS
Primary Contact:
Principal Investigator
Ronald G Garcia, MD, PhD
Massachusetts General Hospital
Ronald G Garcia, MD, PhD
Phone: 617-643-4265
Email: rgarciagomez@mgh.harvard.edu