Certain brain abnormalities may be possible neurobiological markers for bipolar disorder, according to researchers who conducted a systematic review and meta-analysis of published neuroimaging studies.
“Bipolar disorder is often misdiagnosed or tardily detected, leading to inadequate treatment and devastating consequences,” said the research team, including Michèle Wessa, Ph.D., of the Central Institute of Mental Health in Germany.
“The identification of objective biomarkers, such as functional and structural brain abnormalities, of bipolar disorder might improve diagnosis and help elucidate its pathophysiology.”
The team analyzed 13 functional magnetic resonance imaging (fMRI) studies, involving 156 bipolar disorder patients and 164 mentally healthy controls; and 15 structural imaging studies using whole-brain voxel-based morphometry, involving 443 bipolar disorder patients and 551 mentally healthy controls.
Compared with controls, patients with bipolar disorder had decreased activity and/or reduction in gray matter volume in the right inferior frontal gyrus, the right superior frontal gyrus, the anterior cingulate, and the precuneus. These areas are a cortical-cognitive brain network associated with the regulation of emotions, the researchers noted.
On the other hand, bipolar patients also had increased activity in ventral-limbic brain structures (the parahippocampal gyrus and the amygdala) compared with controls. These brain areas mediate the experience of emotions and generation of emotional responses, observes the team.
“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,” Wessa said.
Source: Journal of Affective Disorders