A team of researchers from the University of California, San Francisco (USA) have managed, through a personalized brain implant, to alleviate the overwhelming symptoms of severe depression in a woman, Sarah, 36, by allowing her to see a once again the beauty of the world and of life. “It’s like my lens on the world has changed,” said Sarah, the patient volunteer who asked to be identified only by her first name.
Sarah had been severely depressed for several years.
The scientists implanted temporary thin wire electrodes in his brain. These electrodes allowed the researchers to monitor brain activity corresponding to Sarah’s symptoms of depression, a pattern the researchers could use as a biomarker. In this patient’s case, a particular sign emerged: a fast brain wave called a gamma wave in her amygdala, a brain structure known to be involved in emotions .
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Deep brain stimulation
So they made a custom device for her – the implant was built specifically for Sarah’s brain. Based on deep brain stimulation, the procedure uses electrical communication between two components implanted in the body: an electrode with several points of contact, implanted in the brain, and a programmable pulse generator, implanted somewhere under the skin . Through trial and error, the scientists identified a closely connected brain area, the ventral striatum, where a small dose of electricity appeared to have an immediate and profound impact.
Electrodes implanted in his brain sent electrical impulses to other implanted structures, almost like “a pacemaker for the brain.” High-frequency stimulation to the target area of the brain caused the signals that caused the symptoms of depression to be blocked.
After treatment, the woman showed a “rapid and sustained improvement” in the severity of depression , the researchers explain in their study published in the journal Nature Medicine.
“Future work is required to determine whether the results and focus of this single-patient study are generalizable to a broader population,” clarifies UCSF neuroscientist Katherine Scangos, who led the study.
The device costs around $ 35,000 (about 30,000 euros) and is an adapted version of one commonly used to treat epilepsy, called the NeuroPace RNS System. The approach used by the researchers required a great deal of sophisticated imaging and machine learning technology.
Although the therapy has been tested in a single patient, and would only be suitable for those with severe illness, the success is considered highly significant. Thanks to this advance, depression could soon be treated simply by means of a brain implant , based on the successful results of this pioneering experiment and also to be able to offer personalized treatment for all those difficult-to-treat neuropsychiatric disorders.
According to the World Health Organization (WHO), more than 264 million people worldwide suffer from MDD and another 20 million suffer from schizophrenia. Both are among the most common precursors to suicide.
At the moment, the researchers have already enrolled two more patients and hope to recruit nine more to assess whether the technique can be applied more massively.
Referencia: K.W. Scangos et al. Closed-loop neuromodulation in an individual with treatment-resistant depression. Nature Medicine. Published online October 4, 2021. doi: 10.1038/s41591-021-01480-w
