A team of researchers from the University of California, San Francisco Health has successfully treated a patient with severe depression by targeting the specific brain circuit involved in depressive brain patterns and resetting them thanks to a new proof-of-concept intervention.
Even though it centers around one patient, the groundbreaking study, which has now been published in Nature Medicine, is an important step toward bringing neuroscience advances and the treatment of psychiatric disorders, potentially helping millions of people who suffer from depression.
A union of neuroscience and psychiatric disorders
Traditional deep brain stimulation (DBS) has had limited success in treating the deliberating condition, partly because of the devices used. Most can only deliver continuous electrical stimulation to a single area of the brain at a time. Furthermore, depression may affect different parts of the brain in different people, and there are also many people with the condition who don't respond or have become resistant to treatment. There is no medication or therapy that can help in this situation.
To remedy this, the researchers devised a strategy based on two previously unexplored psychiatric steps: Mapping a patient’s depression circuit and characterizing their "neural biomarker," which is a specific pattern of brain activity that indicates the onset of symptoms.
After identifying the biomarker, the researchers implanted one electrode lead into the brain area where the biomarker was discovered, and another into the patient's 'depression circuit.' Then, they customized a new DBS device to respond only when it recognizes the specific pattern of brain activity, which enabled them to modulate the circuit. With the implanted device in, the first lead would detect the biomarker, while the second would generate a small amount of electricity deep in the brain for six seconds.
Brain implant treats resistant depression
This way, the researchers were able to successfully manage the patient's treatment-resistant depression and create immediate therapy that is tailored to the patient’s brain and the neural circuit causing the illness.
The patient's depression symptoms were alleviated almost immediately and lasted over the 15 months they had the implanted device.
"The effectiveness of this therapy showed that not only did we identify the correct brain circuit and biomarker, but we were able to replicate it at an entirely different, later phase in the trial using the implanted device," said the first author, UCSF psychiatrist Katherine Scangos. "This success in itself is an incredible advancement in our knowledge of the brain function that underlies mental illness."
While it's necessary to emphasize that the remarkable outcome has only been achieved in one patient, the change that one patient has experienced is groundbreaking, indicating just how much it could help millions of people suffering from depression if it manages to pass the research setting and find viability in the outside world.
For the next step, Scangos says, "We need to look at how these circuits vary across patients and repeat this work multiple times. And we need to see whether an individual's biomarker or brain circuit changes over time as the treatment continues."