Depression sufferers have reported significant improvements in their mood after scientists carried out stimulation treatment on an alternative part of the brain.
Scientists at University of California, San Francisco focused their treatment on the orbitofrontal cortex (OFC), situated on the lower surface of the brain above the eyes, on patients with moderate to severe depression.
"The OFC has been called one of the least understood regions in the brain, but it is richly connected to various brain structures linked to mood, depression and decision making, making it very well positioned to coordinate activity between emotion and cognition," said Dr Eddie Chang, neurosurgeon and senior author of the study, published in the Current Biology journal.
A mild electrical current was delivered for three minutes to 25 patients with epilepsy, who had experienced minimal to severe symptoms of depression.
"Patients said things like 'wow, I feel better', 'I feel less anxious', 'I feel calm, cool and collected'," researcher Kristin Sellers said.
"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."
However, scientists have cautioned that research on larger groups will need to be carried out to understand whether stimulation of the OFC produces long-lasting improvements in mood.
"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, academic coordinator at UCSF, who oversaw the research.
"Perhaps by understanding how these emotion circuits go wrong in the first place, we can even one day help the brain 'unlearn' depression."
