Neurocardiac Connectivity in Depression Treatment

By Nithya Somarapu on April 29, 2024

Neurocardiac Connection in Depression Treatment

Heart rate deceleration and sadness may share the same brain network, according to a recent study conducted by Brigham and Women’s Hospital researchers. The researchers discovered that transcranial magnetic stimulation (TMS), which stimulates certain brain regions associated with depression, also alters heart rate in 14 individuals who did not exhibit symptoms of depression. This finding raises the possibility that physicians could target these brain regions without the need for expensive and rarely used brain scans. Nature Mental Health published the results. Additionally, the study highlights the neurocardiac connection in depression treatment.

“Our goal was to figure out how to harness TMS treatment more effectively, get the dosing right, by selectively slowing down the heart rate and identifying the individual best spot to stimulate on the brain,” cited senior author Shan Siddiqi, MD, of the Center for Brain Circuit Therapeutics and Brigham’s Department of Psychiatry. According to Siddiqi, the concept came about as a result of Dutch researchers presenting heart-brain coupling results at a conference in Croatia.

“They showed that not only can TMS transiently lower the heart rate, but it matters where you stimulate,” Shan Siddiqi, MD, senior author of the study from the Center for Brain Circuit Therapeutics and the Brigham’s Department of Psychiatry, stated. According to Siddiqi, the concept originated at a symposium in Croatia when academics from the Netherlands were showcasing their heart-brain connection findings.

“They showed that not only can TMS transiently lower the heart rate, but it matters where you stimulate,” The possibility of making this precision-focused treatment for depression more accessible to the rest of the globe is what excites Siddiqi the most about the study, he continued.

“We have so many things we can do with advanced technology available here in Boston to help people with their symptoms,” he said. “But some of those things couldn’t easily get to the rest of the world before.”

To finish the study, Siddiqi worked with main author Eva Dijkstra, MSc, and his colleagues in the Brigham Center for Brain Circuit Therapeutics. To integrate their research on the heart-brain connection with the brain circuitry being studied by the CBCT team, Dijkstra, a Ph.D. candidate, traveled to Pittsburgh from the Netherlands. This collaboration aimed to explore the neurocardiac aspects of depression treatment.

Based on prior research on the relationship between connectivity and depression, researchers analyzed functional MRI scans of 14 participants to find regions of the brain thought to be the best targets for treating depression. To treat depression, ten locations in each participant’s brain were identified, including both “connected areas” and optimum areas. After stimulating each area, the researchers saw what effect it had on heart rate, focusing on the neurocardiac implications of depression treatment.

“We wanted to see if there would be mostly heart-brain coupling in the connected areas,” Dijkstra said. “For 12 out of 14 usable data sets, we found we would have a very high accuracy of defining an area that is connected by just measuring heart rate during brain stimulation.”

According to Dijkstra, the discovery may aid in the customization of TMS therapy for the treatment of depression by identifying a specific treatment location on the brain and facilitating its accessibility as an MRI would not be required before treatment.

According to Siddiqi, the results of this study could also be utilized in the development of therapies that emergency physicians and cardiologists would find helpful in the future.

The study’s small sample size and the fact that not every region of the brain was stimulated are two of its limitations.

Finding the areas of the brain to activate to improve the consistency of heart rate fluctuations will be the team’s next task.

A larger study involving 150 individuals with depression disorders, many of whom are resistant to therapy, is currently being conducted by Dijkstra’s team in the Netherlands. Later this year, data from that study will be analyzed, which could advance the research toward clinical translation, particularly regarding neurocardiac aspects of depression treatment.

For more information: Probing prefrontal-sgACC connectivity using TMS-induced heart-brain coupling, Nature Mental Health, https://doi.org/10.1038/s44220-024-00248-8

Nithya Somarapu

With a deep fascination for the intricacies of the medical field, Nithya excels at translating complex medical information into clear and engaging content. Her passion for clear communication fuels her ability to craft compelling narratives for a diverse audience. Nithya's meticulous research ensures the accuracy and depth of the content she creates, empowering readers to stay informed about important medical advancements.