May 4, 2011 12:52 GMT  ·  By
Many people involved with the arts, such as Vincent van Gogh,[1] are believed to have suffered from bipolar disorder
   Many people involved with the arts, such as Vincent van Gogh,[1] are believed to have suffered from bipolar disorder

A meta-analysis of studies conducted thus far on bipolar disorder has revealed that the condition can be identified by detecting certain abnormalities in the brain. These variations from the norm can be thought of as neurobiological markers for the disease.

This systematic review of the work conducted in the field provides some fairly interesting conclusions about bipolar disorder, an affliction that is oftentimes difficult to diagnose. But the abnormalities provide experts with a tangible way of assessing a person's diagnostic.

What scientists hope to obtain from investigations such as this one is the development of a diagnostics method that will not detect the condition only in its latter stages. Early detection is equally important for this disorder as is is for cancer and other medical conditions.

“Bipolar disorder is often misdiagnosed or tardily detected, leading to inadequate treatment and devastating consequences,” explains expert Michèle Wessa, PhD, who was part of the research team.

The expert, who is based at the Central Institute of Mental Health in Germany, adds that “the identification of objective biomarkers, such as functional and structural brain abnormalities, of bipolar disorder might improve diagnosis and help elucidate its pathophysiology.”

Investigators analyzed a total of 28 studies on the condition. Thirteen of them had been conducted using functional Magnetic Resonance Imaging (fMRI), covering a total of 164 healthy individuals and 156 men and women suffering from bipolar disorder.

The remaining 15 studies were conducted using an investigations technique called whole-brain voxel-based morphometry. They covered a total of 443 patients and 551 healthy control subjects.

“These results support and refine previously proposed neurobiological models of the disorder and suggest that an imbalance between cortical-cognitive and limbic brain networks may serve as a neurobiological marker of bipolar disorder,” explains Wessa, quoted by PsychCentral.

One of the most important discoveries was that gray matter volume in the right inferior frontal gyrus tended to become smaller and/or less active in bipolar patients. However, structures such as the parahippocampal gyrus and the amygdala, both part of the ventral-limbic system, were more active.

These areas of the brain are associated with emotion and fear regulations, as well as with controlling the flight-or-flight response individuals display when faced with a dangerous situation.