Transcranial Magnetic Stimulation (TMS) to Improve Mental Health- Advancing Individualized Treatment
In our 8th Fresh Perspectives webinar with Amara Davis, we discuss Dr. Nicholas Balderston’s work on transcranial magnetic stimulation (TMS) and its application in major depressive disorder. TMS is a non-invasive method to modulate brain activity through a magnetically generated electric field by placing a coil on the scalp in which specific brain regions can be targeted. Dr. Balderston, an assistant professor of psychiatry at the University of Pennsylvania School of Medicine, presents the team’s recent findings published in the article “Proof of concept study to develop a novel connectivity-based electric-field modelling approach for individualized targeting of transcranial magnetic stimulation treatment” in the journal Neuropsychopharmacology. In this computational study, Dr. Balderston and colleagues develop an electric field (e-field) model that aims to maximize the therapeutic benefit of targeted TMS individualized for the person. Basic model assumptions the research team seeks to demonstrate and utilize to help treat people are: (1) the amount of energy delivered in a particular region will proportionally increase neural activity, and (2) improving the connectivity of symptom-associated-regions will improve clinical outcomes. Improvements in the investigators’ modeling compared to prior studies are to look at changes in connectivity across the entire brain and to link functional connectivity with depression symptoms. The researchers’ model found that orientation accounted for as much variability as scalp location, such that a combination of site and orientation yields maximal predicted symptom reduction for individualized treatment. The investigative team is making the model available to the broader scientific community to encourage testing and validation.
Public Interest and Clinical Innovation:
Major depressive disorder (MDD) is highly prevalent and affects approximately 16.9 percent of the U.S. population. About 30% of persons with MDD aren’t effectively treated by conventional medications. Thus, MDD represents a significant clinical challenge with substantial unmet medical need necessitating advances in treatment. In 2009, the United States Food and Drug Administration approved the use of repetitive transcranial magnetic stimulation (rTMS) for the treatment of MDD, often used when medications have failed, but also can be used as a first line therapy. Like antidepressant medications, the results of rTMS is more effective for some than others and pressing need exists for improving rTMS treatment. Individualized targeting of rTMS is promising for improving the treatment outcomes for more persons with MDD. Combining fMRI data with symptom scores, the researchers were able to model site and coil orientation predicted to most effectively reduce MDD symptoms. Notably, the researchers address limitations of prior efforts to identify new downstream targets of the dorsal lateral prefrontal cortex (dlPFC) by using resting state functional connectivity electric field mapping to predict how optimal administration of TMS will affect connectivity across the entire brain where others have considered these ‘off-target’ brain regions. As the key assumptions and model predictions are pursued and validated, this research may aid personalized therapy for MDD and find new applications in other psychiatric conditions, thereby benefiting society, families, and persons.
About Dr. Balderston:
Dr. Balderston is an experimental psychologist focusing on anxiety. His research uses psychophysiology, neuroimaging, and neuromodulation to develop and test brain-behavior hypotheses aimed at understanding the mechanisms that mediate clinical anxiety. Dr. Balderston took an unconventional route into neuroscience. After a period of working in construction, he returned to college where his interest was first piqued during an undergraduate neuroscience class, then followed by his studying mental health for his doctoral dissertation work, and subsequently a post-doctoral fellowship at the National Institute of Mental Health. Upon joining the faculty at the University of Pennsylvania, he has started the Center for Neuromodulation in Depression and Stress (CNDS) in the Department of Psychiatry at the Perelman School of Medicine.
To see Amara’s full Interview with Dr. Nicholas Balderston on advancing individualized TMS treatment to improve therapies for mental health, see the video below or on the LMI YouTube Channel: https://youtu.be/9q-8ns2OAB8.
Balderston, N.L., Beer, J.C., Seok, D. et al. Proof of concept study to develop a novel connectivity-based electric-field modelling approach for individualized targeting of transcranial magnetic stimulation treatment. Neuropsychopharmacol. 47, 588–598 (2022). https://doi.org/10.1038/s41386-021-01