Acupuncture is a traditional and significant part of Chinese medicine that’s been around for thousands of years, and continues to be used to ease the pain and discomfort that come with a wide variety of conditions, including fibromyalgia and osteoarthritis.

The practice has also shown potential for easing the symptoms of depression. What hasn’t been clear, however, is why.

In a new study published in Medicine, researchers led by a team from the Beijing University of Chinese Medicine analyzed brain imaging data from seven previous clinical trials, involving a total of 357 participants with major depressive disorder.

When comparing the brain scans of people who had been given acupuncture treatments against those on antidepressants or those receiving a placebo version of acupuncture, the researchers found something interesting: acupuncture seemed to be rewiring specific brain regions.