fMRI comparing unmedicated adults who experienced depression when young & those who didn't found hyper-connected emotional and cognitive networks

FTA:

The researchers found many regions that are “hyper-connected – or talking to each other a little too much – among those who have a history of depression,” Jacobs said. These hyper-connected brain networks were related to rumination, with individuals thinking about a problem over and over without actively trying to come up with a solution.