Could this ‘pacemaker for the brain’ be the solution to severe depression?

Approximately 280 million people worldwide are living with depression.

Typically characterized by prolonged periods of extreme low mood, other symptoms of depressive illness include: feelings of hopelessness, low self-esteem, a lack of motivation or interest in things and an absence of enjoyment from life.

It can be successfully treated with a range of therapies, from counselling to medication, and can be helped by changes in lifestyle. But for many people, depression can become a life-long struggle.

Now a scientific breakthrough could offer a solution for those with treatment-resistant depression.

US researchers and clinicians at the University of California San Francisco (UCSF) have developed an alternative to traditional approaches to treating depression – an implant that acts like a pacemaker for the brain.

It has so far been tested on one patient – with positive results.

“We’ve developed a precision-medicine approach that has successfully managed our patient’s treatment-resistant depression by identifying and modulating the circuit in her brain that’s uniquely associated with her symptoms,” said Dr Andrew Krystal, Professor of Psychiatry at the UCSF Weill Institute for Neurosciences and senior author of the study.

The implant is embedded in the skull and wired to the patient’s brain.

The device UCSF has developed uses deep brain stimulation (DBS) to trigger electrical charges that reset brain function for the patient.

There are two electrodes implanted in the patient’s brain: one monitors neural circuits to detect changes in brain function that are associated with depressive episodes. The other can deliver a tiny electrical charge (one milliampere for six seconds) to adjust brain activity and – it is hoped – ease the bout of depression.

Depression can affect activity in different areas of the brain. Traditionally, DBS devices have only been able to deliver a constant trickle-charge to one brain area. The UCSF implant, however, can monitor a patient’s brain and react only when needed.

The UCSF team have run a 15-month trial of the device with a patient who they refer to as Sarah.

“I was at the end of the line,” said Sarah, of life before the implant. “I was severely depressed. I could not see myself continuing if this was all I’d be able to do, if I could never move beyond this. It was not a life worth living.”

Studies at UCSF had identified distinct patterns of brain activity that were affected by a patient’s mood changes. The discovery of this biomarker meant it was possible to develop treatments that would stimulate the brain to relieve depression in ways that were tailored to specific patients.

The implanted electrodes in Sarah’s brain could therefore be targeted precisely where they would be most effective.

The result was “a rapid and sustained improvement in depression,” the study authors said. The patient had an almost immediate alleviation of symptoms, she reported, which then lasted throughout the duration of the trial.

“For me, the device has been an amazing blessing,” said Sarah.

Two further patients have been enrolled in the trial, with the team hoping to add nine more in time.