The research is based on a comprehensive review of magnetic resonance imaging (MRI) scans. MRI is a medical imaging technique to produce pictures of the anatomy and the physiological processes, to allow for assessments of health and disease to be made. MRI scanners use powerful magnetic fields, radio waves, and field gradients to generate images of the organs in the body.
With the new study, MRI scans indicate people with the bipolar disorder have differences in the brain regions that control inhibition and emotion. This suggests a physical cause for the condition.
Bipolar disorder (sometimes called manic depression) is a mental disorder that leads to periods of depression and periods of elevated mood. At times of the elevated mood a person feels abnormally energetic, happy, or irritable. In contrast, during periods of depression the affected individual can experience periods of crying and adopt a negative outlook on life. The cause divides psychology (which leans towards environmental factors) and psychology (which leans towards physical factors). The Norwegian research is concerned with physical alterations to the brain.
According to lead researcher, Professor Ole A. Andreassen, with the new study his research group has “created the first global map of bipolar disorder and how it affects the brain, resolving years of uncertainty on how people’s brains differ when they have this severe illness.”
To derive at the difference in gray matter between those with diagnosed bipolar disorder and those without, the researchers examined the MRI scans of 6,503 individuals. This population included 2,447 adults with bipolar disorder and 4,056 healthy controls. Various factors were accounted for, including use of prescription medications, age of illness onset, history of psychosis, age and sex differences.
The outcome, expressed as a series of brain maps, was that thinning of cortical gray matter in the brains of those with bipolar disorder was significant as compared against healthy controls. The major deficits were with parts of the brain that function to control inhibition and emotion (located in the frontal and temporal regions). Future research will see if new medications can address this.
The study has been published in the journal Molecular Psychiatry. The research paper is titled “Cortical abnormalities in bipolar disorder: an MRI analysis of 6503 individuals from the ENIGMA Bipolar Disorder Working Group.”
