(dailyRx News) If a sad person and a depressed person get their brains scanned while thinking about behaving badly towards a close friend, the scans will look different. People with major depressive disorder (MDD) feel an exaggerated sense of guilt that fuels their depression.
A new study looks at the areas of the brain that are tied to guilt in brain scans of patients with MDD. Brain scan results may prove effective in properly diagnosing MDD and predicting future episodes.
Roland Zahn, MD, Medical Research Council (MRC) Clinician Scientist Fellow, led a team at the University of Manchester to understand the role of guilt in depression through brain scans.
Sigmund Freud spearheaded the notion that self blame and exaggerated guilt are at the root of depression. Brain scans of people with MDD may end up proving Freud right.
Dr. Zahn’s team did functional magnetic resonance imaging (fMRI) brain scans of people that had previously been diagnosed with MDD, but had not had an episode in over a year, nine of which were on medication and 16 were not on medication. Twenty-two control subjects were also scanned with no personal or family history of MDD.
Each participant was asked to think about acting badly, such as being ‘stingy’ or ‘bossy’ towards close friends as the fMRI was being performed.
Certain emotions register in specific parts of the brain. By looking at what parts of the brain are active in patients with MDD compared to people without MDD researchers were able to determine which emotions are tied to depression.
Dr. Zahn explains why this is important: “Our research provides the first brain mechanism that could explain the classical observation by Freud that depression is distinguished from normal sadness by proneness to exaggerated feelings of guilt or self-blame.”
He goes on to say that with the fMRI they link the parts of the brain that understand and manage socially appropriate behavior with feelings of guilt in people who are prone to depression. “The scans revealed that the people with a history of depression did not ‘couple’ the brain regions associated with guilt and knowledge of appropriate behaviour together as strongly as the never depressed control group do.”
Authors conclude: “Interestingly, this ‘decoupling’ only occurs when people prone to depression feel guilty or blame themselves, but not when they feel angry or blame others. This could reflect a lack of access to details about what exactly was inappropriate about their behaviour when feeling guilty, thereby extending guilt to things they are not responsible for and feeling guilty for everything.”
This research lays the groundwork for future understandings about depression with tangible neurological scans. Future use of this kind of scan could help predict major depressive episodes or help people at risk for developing MDD.
This study was published in the Archives of General Psychiatry, June 2012. Funding for this study was provided by the Medical Research Council in the UK, no conflicts of interest were found.