A lot of research has previously been carried out looking at brain differences in individuals with bipolar disorder using magnetic resonance imaging (MRI). Brain scans have shown that people with bipolar often have differences in brain areas that are responsible for regulating emotion. It is thought that because of this, individuals have are less able to control and monitor emotions and moods.
A new study used functional magnetic resonance imaging (fMRI) to look at which areas of the brain were activated whilst patients were in a low mood and whilst patients were in a high mood; they had to try and control their responses to emotional and non-emotional pictures whilst they were in the brain scanner.
Results showed that patients who were in a depressed state (low mood) activated abnormal areas of the brain when they had to try and control their responses to seeing sad faces. Patients who were in a manic state (high mood) showed abnormal brain activation to all types of stimuli; i.e. when they had to control their responses to sad faces, happy faces and even non-emotional stimuli.
The results imply that certain brain areas may be important for controlling responses to emotional information and mood disorders effect the normality in functioning of these areas. A manic mood and a depressed mood both have different effects on emotion regulation in the brain.
This study may also encourage circuit-based treatments for bipolar disorder, such as neurostimulation and psychotherapy.
More information: Hummer, Hulvershorn, Karne, Gunn, Wange and Anand (2013). Emotional Response Inhibition in Bipolar Disorder: A Functional Magnetic Resonance Imaging Study of From: Trait- and State-Related Abnormalities. Biological Psychiatry, 73.