Turns out, analysing the stimulation of the brain functions might relieve depression symptoms in people.
The researchers at the University of California recruited 25 patients, who reported minimal to severe symptoms of depression, and asked them to report their mood several times a day using a tablet-based app while they were in the hospital awaiting surgery. This allowed the researchers to use the patients' implanted electrodes to observe patterns of brain activity linked to natural mood fluctuations over several days.
The researchers then used mild electrical current to systematically disrupt brain activity in candidate regions including the orbitofrontal cortex "OFC", amygdala, cingulate cortex, insula, and hippocampus -- while asking patients to report the effect on their mood ranging between opposing states such as 'calm' vs. 'restless' or 'hopeful' vs. 'hopeless.'
The researchers found that most stimulation locations produced no effect on volunteers' mood, but applying current to the lateral OFC for just three minutes, produced significant improvements in the mood of the patients with moderate to severe depression.
"Patients said things like 'Wow, I feel better,' 'I feel less anxious,' 'I feel calm, cool and collected,'" recalled Kristin Sellers, lead researcher of the study. "And just anecdotally, you could see the improvements in patients' body language. They smiled, they sat up straighter, they started to speak more quickly and naturally."
Patients with moderate to severe depression reported significant improvements in mood when researchers precisely stimulated a brain region called the orbitofrontal cortex (OFC).