Relieving Depression with Brain Stimulation

What They Did: A team of researchers from the University of California, San Francisco led by NYSCF – Robertson Neuroscience Investigator and Professor of Neurological Surgery Dr. Edward Chang used implanted electrodes to stimulate brain activity in epilepsy patients suffering from depression. 

What They Found: In epilepsy patients with moderate to severe depression, brain stimulation of a region called the orbitofrontal cortex significantly improved mood.

Why It Matters: This method could one day be used as an effective treatment for a broader population of depression patients and gives insight into the neural basis behind the condition. 

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“Wow, I feel better.”

“I feel less anxious.”

“I feel calm, cool, and collected.”

These were all sentiments expressed by patients who took part in an exciting new depression study led by NYSCF – Robertson Neuroscience Investigator and University of California, San Diego (UCSF) Professor of Neurological Surgery Dr. Edward Chang and published in Current Biology. This study used surgically implanted brain electrodes to stimulate a region called the orbitofrontal cortex (OFC), which is connected to brain structures that control mood, depression, and decision making.

The subjects involved in the study were epilepsy patients preparing to undergo a certain brain surgery. Part of the standard preparation for this surgery involves fitting the brain with electrodes that help surgeons identify which tissue is contributing to a patient’s seizures.

The researchers were able to use these electrodes to deliver an electrical current to different parts of the brain associated with depression. While stimulation of most of the regions offered no relief, one region—the OFC—produced significant mood improvements in patients with moderate to severe depression.

Stimulating the OFC also triggered a cascade of brain activity that resembled how the brain naturally behaves during positive mood states. Notably, as stimulation only improved mood in patients who reported experiencing depressive symptoms and not in others, the study suggests that the OFC plays a distinct role in the onset of depression – perhaps acting as an impediment to positive mood that can be disabled by stimulation.

The team hopes that their study will help scientists better understand the neural basis behind depression and develop targeted, personalized therapies that could offer relief to patients who have found current medications ineffective.

“The more we understand about depression at this level of brain circuitry, the more options we may have for offering patients effective treatments with a low risk of side effects,” said Heather Dawes, PhD, who helped to oversee the research, in a statement. “Perhaps by understanding how these emotion circuits go wrong in the first place, we can even one day help the brain ‘unlearn’ depression.”