What is Transcranial Magnetic Stimulation?
Ever heard of transcranial magnetic stimulation, also known as TMS? It’s a therapy where doctors apply strong magnetic pulses to your scalp.
These pulses stimulate your brain and could help people with serious depression who haven’t found relief through standard treatments.
But until recently, it’s been a mystery how exactly TMS changes our brain to lift the veil of depression.
New Study on TMS and Depression
A recent study led by Stanford Medicine researchers has offered us a new clue. They found that TMS works by reversing the flow of abnormal brain signals in our minds.
This groundbreaking discovery might also help doctors diagnose depression more effectively.
The scientists think that these backwards streams of neural activity could serve as a biomarker, which is a physical sign of a condition.
The Researchers and the Tools
The lead investigator of this study was Dr. Anish Mitra, a postdoctoral fellow in psychiatry and behavioral sciences.
He was skeptical about TMS at first and wanted to investigate it further. Luckily, he had a special tool for the job.
Dr. Mitra had developed a mathematical tool to analyze functional magnetic resonance imaging, or fMRI. This is a common technique used to map active areas in our brains.
His tool used the tiny differences in timing between the activation of different brain areas to also reveal the direction of that activity.
What Did They Do?
Dr. Mitra and his colleagues worked with 33 patients diagnosed with treatment-resistant major depressive disorder. Treatment-resistant means that other treatments had failed for these patients.
Out of the 33 patients, 23 received a specific form of TMS treatment known as Stanford neuromodulation therapy (SNT), while 10 received a sham treatment, which is like a placebo.
The SNT treatment involves high-dose patterns of magnetic pulses that can modify brain activity related to major depression.
Unlike traditional TMS, which requires daily sessions for weeks or months, SNT is much quicker, working over ten sessions each day for just five days.
Their Findings: A Change in Brain Signals
When they examined the fMRI data from all these patients, the researchers noticed a unique connection in the normal brain.
There, a region called the anterior insula, which helps us understand bodily sensations, sends signals to another region that manages emotions, the anterior cingulate cortex.
In 75% of the depressed participants, this usual flow of activity was reversed. The more severe the depression, the higher the proportion of signals that traveled in the wrong direction.
However, after the depressed patients were treated with SNT, the flow of neural activity shifted to the normal direction within a week. This change coincided with their depression lifting.
What Does This Mean for Depression Treatment?
A big challenge in treating depression is that we don’t fully understand its biological mechanisms.
If someone has a fever, there are many tests that can determine the cause and treatment. But for someone with depression, there aren’t any similar tests.
The results of this study suggest that this abnormal flow of neural activity could serve as a biomarker for depression.
This could allow doctors to tailor treatment more effectively to individual patients, and predict how likely they are to respond well to SNT treatment.
Future Steps
These findings are promising, but the researchers want to verify them with more patients.
They’re also hoping that other scientists will adopt their analytic technique to uncover more insights about the direction of brain activity hidden in fMRI data.
After all, the more we know about the brain, the better we can understand and treat conditions like depression.
If you care about depression, please read studies about the key to depression recovery, and this stuff in your diet may cause depression.
For more information about mental health, please read studies that ultra-processed foods may make you feel depressed, and Vitamin D could help reduce depression symptoms.
The study was published in PNAS.
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