New York, Aug 28 (IANS): Several regions of the brain in young adults who have a history of depression are "hyper-connected" -- or are talking to each other a little too much, new research finds.

These "hyper-connected" brain regions are related to rumination where individuals think about a problem over and over without actively trying to come up with a solution.

"We wanted to see if the individuals who have had depression during their adolescence were different from their healthy peers," said Rachel Jacobs, a research assistant professor in psychiatry at University of Illinois at Chicago (UIC).

To understand this, researchers used functional magnetic resonance imaging to examine the brain connectivity of young adults ages 18 to 23 while they were in a resting state.

Thirty young adults who had previously experienced depression and 23 healthy people were analysed.

"Rumination is not a very healthy way of processing emotion," noted Scott Langenecker, an associate professor of psychiatry and psychology at UIC.

Rumination is a risk factor for depression and for re-occurrence of depression if you have had it in the past.

The researchers also looked at cognitive control (the ability to engage and disengage in thought processes or behaviours), which is a predictor of response to treatment and also relapse of illness.

"Cognitive control and rumination, as you might expect, are related to each other. As rumination goes up, cognitive control goes down," Langenecker noted.

According to him, if we can help youth learn how to shift out of rumination, this may protect them from developing chronic depression and help them stay well as adults.

The research was published online in the journal PLOS ONE.