A new, small study is shedding light on how guilt -- how the brain processes and responds to it -- factors into depression.
Researchers from the University of Manchester conducted brain scans on people who were in remission from depression, and found that their activity in the brain regions linked with guilt and knowledge about what is appropriate behavior was different from people who had never had depression.
"Our research provides the first brain mechanism that could explain the classical observation by [Sigmund] Freud that depression is distinguished from normal sadness by proneness to exaggerated feelings of guilt or self-blame," study researcher Dr. Roland Zahn, of the University of Manchester School of Psychological Sciences, said in a statement.
The study, published in the journal Archives of General Psychiatry, included 25 people who were in remission from major depressive disorder, and 22 control participants. Researchers conducted functional magnetic resonance imaging (fMRI) brain scans while the participants were asked to imagine certain scenarios. Some scenarios included acting "bossy," or acting "stingy"; they were also asked to report how they felt about acting this way.
The researchers found that the people who had depression before did not experience a strong "coupling" of the brain region responsible for guilt -- the subgenual brain region -- with the one responsible for knowledge of appropriate behavior -- the anterior temporal lobe.
"Interestingly, this 'decoupling' only occurs when people prone to depression feel guilty or blame themselves, but not when they feel angry or blame others," Zahn said in the statement. "This could reflect a lack of access to details about what exactly was inappropriate about their behavior when feeling guilty, thereby extending guilt to things they are not responsible for and feeling guilty for everything."
Previously, Zahn had a study published in the journal Cerebral Cortex explaining the links between brain regions responsible for knowledge of appropriate behavior and moral feelings, PsychCentral reported.
That "study used functional brain imaging to identify the circuits in the brain that underpin our ability to differentiate social behavior that conforms to our values from behavior that does not," Zahn told PsychCentral.