Analysing brain scans of people with depression and those who had never met someone with depression, scientists have found that people with the condition have poorer processing of emotions than people who are emotionally close to someone.
Their findings were published in the journal Psychological Science.
A previous study had found that being close to a loved one who is depressed was linked to poorer brain function, and that it was also linked to an increased risk of depression.
The new study was conducted by researchers at the University of California, San Diego.
They recruited a group of 15 people who were diagnosed with depression.
All were in their early 20s, and all had at least one other mental health disorder.
All completed two brain scans: a PET scan, which measures blood flow in the brain, and an MRI scan, a microscopic image of the brain.
The researchers compared the brain scans to a control group of 19 people, and found that the people who had been diagnosed with a mental illness had significantly lower connectivity between the two regions.
These findings suggest that people diagnosed with mental illness are more likely to have lower connectivity in the prefrontal cortex and limbic system, as well as a weaker connection between the amygdala and the insula, a part of the amygdala that regulates emotion.
Researchers say this may help explain the relationship between depression and empathy.
“These findings support previous studies showing that people who have depression are more prone to depression and that empathy is related to a lower emotional empathy,” said study co-author Jennifer Stolz, a professor of psychology at UC San Diego and an associate professor of psychiatry.
“Our results show that this association is stronger in people who report depression and in those who have never met a depressed person.”
Researchers also found that depression patients with high connectivity between brain regions were more likely than depressed people with low connectivity to have more connections between the insular cortex and the amygdala, a region that regulates emotions.
This may help account for the relationship of depression and emotional empathy, they say.
The research was supported by the National Institute of Mental Health.
The study was published in Psychological Science and was funded by the Department of Veterans Affairs, the National Institutes of Health, and the US Department of Energy.
This article first appeared on New Scientist