Mechanism of Action of Transcranial Alternating Current Stimulation for the Treatment of Major Depressive Disorder

2018 Award: $100,000

Major depressive disorder (MDD) has devastating effects on patients and their families, including an increased risk of suicide. Thanks to previous FOH funding, promising results have demonstrated that transcranial alternating current stimulation (tACS) is a safe and effective therapy for MDD symptoms. This study is an expansion of previous projects, and will collect brain rhythm data to determine individualized response levels to the stimulation.

Need/Problem: Depression is a serious illness and many patients do not find relief with the current treatment options. Our Carolina Center for Neurostimulation has pioneered a novel form of non-invasive brain stimulation that applies a very weak but smart current to modulate brain rhythms. This potential new treatment is very safe (most patients cannot even feel the electricity) and potentially efficacious for the treatment of depression. Based on promising pilot data, we are excited to move ahead with this new study to better understand how the stimulation modulates brain rhythms such that we can further optimize the stimulation to develop personalized treatment protocols.

Grant Summary: In collaboration with Dr. David Rubinow, Chair of the Department of Psychiatry at UNC – Chapel Hill, we are conducting a randomized, placebo controlled clinical trial to investigate how transcranial alternating current stimulation (tACS) modulates alpha rhythms in the brain of patients with depression. By using advanced electronic sensors and recording hardware, we will track changes in brain rhythms in patients as they receive tACS for the treatment of their depression.

Goals and Projected Outcomes: Our goal is to understand how individual patients respond to the stimulation and how their electric brain activity changes in response to stimulation. Understanding not only if this potential new treatment reduces depression symptoms but also how it alters brain circuits will allow us to develop the next generation stimulation paradigms that are individualized for each patient to achieve maximal efficacy. This rational design approach that integrates medicine, biology, and engineering represents the unique and interdisciplinary expertise in the Carolina Center for Neurostimulation.

Flavio Frohlich, PhD

Grant Details: In this proposed study, we will test the efficacy of 10Hz-tACS against placebo stimulation in a 5-day, 40-minute per stimulation protocol. We propose a target engagement trial, with electroencephalogram (EEG) administered before and after each stimulation session, so to understand the short-term and cumulative effects of tACS in this population. In addition, we are adding several biological and physiological measures in conjunction with clinical/self-report measures to delineate how inter-individual differences shape the target engagement by 10Hz-tACS. This study will address a crucial gap between our basic science work on the mechanisms of tACS and our exciting clinical findings from our previous study.