Despite being healthy and reporting similar conscious reactions to the recorded comments, the formerly depressed showed different activity in their brains, compared to those who had never been depressed. "When we asked them how they felt after being criticized, they responded in the same way as the controls did," said Hooley. "But when we looked at the brain scans, the patterns of activation were quite different. So this is happening under the radar of awareness."
Individuals who had never been depressed showed increased activity in the dorsolateral prefrontal cortex and the anterior cingulate cortex, which are brain areas involved in the cognitive control of emotion. The formerly depressed individuals did not show activity in these areas, but instead showed increased activity in the amygdala, a part of the brain that is responsive to potentially threatening stimuli. Previous research has shown similar activity in these neural systems among individuals who are currently depressed.
"When these formerly depressed participants are processing criticism, some brain areas thought to be involved in emotion regulation are less active, and the amygdala is actually more active, compared to the healthy controls," says Hooley. "We know that this is not linked to them being symptomatic now. These findings tell us that even when people are fully recovered from an episode of depression, their ability to process criticism is still different and probably not in a good way."
What the researchers don't know is whether this type of activity within these brain systems exists prior to the development of a depressive episode, or if this activity could be a kind of scar left on the brain by a past episode of depression, says Hooley.
Previous studies have shown that living in a critical family environment increases rates of relapse in depression, and so use of criticism in this study is particularly important and applicable to real life.
| Contact: Amy Lavoie amy_lavoie@harvard.edu 617-496-9982 Harvard University Source:Eurekalert |