If you’re deeply and chronically depressed, signals between two parts of your brain probably are flowing backwards.

Now researchers at Stanford University have found a method to get the signals flowing in the right direction, relieving chronic depression that had refused to yield to other treatments.

They use magnets.

So-named “transcranial magnetic stimulation” has been in therapeutic use for years, easing phobias, cutting food cravings, and sharpening memory, among other benefits.

In 2020, Stanford scientists trying a new tweak to the method found it vastly improved symptoms in 90 percent of the people who tried it.

Now they know why.

The researchers analyzed brain scans of 33 people who had severe depression not reached by conventional treatments. They compared those scans with data from 85 people who showed no symptoms of depression.

They found the key difference in the part of the brain called the anterior insula, which helps regulate emotions by sending signals to another brain region called the anterior cingulate cortex, which governs emotions.

In three-quarters of the people suffering severe depression, they found that the anterior cingulate cortex was signaling the anterior insula. The more signals it was sending, the worse the depression.

“It’s almost as if you’d already decided how you were going to feel, and then everything you were sensing was filtered through that,” Anish Mitra, one of the researchers, told Science magazine. “The mood has become primary. 

“That’s consistent with how a lot of psychiatrists see depression,” he added. “Even things that are quite joyful to a patient normally are suddenly not bringing them any pleasure.”

To test the discovery, the group administered targeted neuromagnetic stimulation to 23 severely depressed people over five days. Ten people, also severely depressed, received a placebo treatment.

Within three days of ending the treatment, the relevant brain signals had reversed direction and the people who received the treatment reported better mood. The worse the depression had been, the greater the improvement.

The treatment showed no severe side effects.

The scientists are now planning to test a larger group of volunteers.

TRENDPOST: In the U.S. alone, more than 14 million people are estimated to suffer from severe depression, at least occasionally, according to the National Institutes of Health.

Globally, about 5 percent of adults are afflicted, more often women than men.

A relatively simple “brain zap” to treat the illness could not only avoid the dangers of psychotropic drugs, but also restore patients’ social and economic productivity as well as their quality of life.