New York, Oct 6 (IANS): For the first time ever in the world, a woman suffering from a severe form of depression was treated using electric brain implantation, giving hope to millions of people suffering from the mental illness who do not respond to other therapies.

Sarah, 38, who asked not to be fully identified, has been implanted with a battery-operated, matchbook-sized device which detects when she is becoming depressed.

The experimental therapy led by researchers at the University of California, San Francisco uses a magnet to download her brain activity and delivers bursts of electrical stimulation, The New York Times reported.

Five years, suffering from depression, Sarah had suicidal tendencies, she quit her job and doctors considered it unsafe for her to live alone.

"I couldn't stop crying. The thought that consumed me the entire way on that road was just driving my car into the marshland so I can drown," she was quoted as saying.

"She tried nearly every treatment: roughly 20 different medications, months in a hospital day programme, electroconvulsive therapy, transcranial magnetic stimulation. But her symptoms persisted," the NYT report said.

The device was fully operational in August 2020. Within 12 days Sarah's score on a standard depression scale dropped to 14 from 33, and several months later, it fell below 10, essentially signalling remission, the researchers reported.

"Within a few weeks her suicidal thoughts just disappeared. The device has kept my depression at bay, allowing me to return to my best self and rebuild a life worth living," Sarah was quoted as saying.

Sarah's is the first documented case of personalising a technique called deep brain stimulation, used to treat Parkinson's disease and several other disorders, to successfully treat depression.

According to Dr Samir Parikh, director, Mental Health and Behavioural Sciences, Fortis Healthcare, depression happens when neurotransmitter imbalances, psychological factors, etc all have an interplay.

"While medicines and psychotherapy have been used for the past several decades now with significant success, there are some people who do not respond to this treatment. And for this, there are some of these newer advances like our TMS (transcranial magnetic stimulation) and deep brain stimulation, which are also now approved, and act as an alternative for those people who have not been able to get maximum benefit out of the medication and psychotherapy," Parikh told IANS.

However, even alongside these treatments, "other aspects like medicines and counselling and therapy may continue even post-surgery," he said.

To identify the specific brain activity pattern linked to Sarah's depression, researchers conducted an intensive 10-day exploration of Sarah's brain, placing multiple electrodes in it and asking about her feelings when they applied stimulation to different locations in varying doses.

The team identified a specific pattern of electrical activity that coincided with Sarah becoming depressed.

While deep brain stimulation is typically delivered continuously, Sarah's device is set to supply only a six-second burst when it recognises her depression-linked brain activity pattern, the report said.

The goal is that stimulation will disrupt or shift the neural activity to produce a healthier pattern that will ease depressive symptoms.

Sarah has continued taking psychiatric medications, and the stimulation hasn't eliminated depression-causing activity in her brain. But she can manage her illness much better, she said, instead of being unable to make even the smallest decisions, like what to eat, the report said.