Bipolar type I patients’ relatives lack brain connectivity disruptions


Anatomical connectivity in discreet frontal regions of the brain is disrupted in bipolar I disorder patients, but not in mentally healthy relatives of such patients, according to a study.

The researchers looked for connectivity abnormalities in the brains of multiply affected bipolar I disorder families “to assess the utility of dysconnectivity as a biomarker and its endophenotypic potential.” Tractography was done on magnetic resonance diffusion images of the brains of 19 bipolar I patients in remission, 21 of the patients’ first-degree relatives who did not have bipolar I, and 18 unrelated controls who also did not have bipolar I. A connectivity matrix was generated for each patient, and the Brain Connectivity Toolbox was used to extract neural network metrics.

“Whole brain analysis revealed no differences between groups,” according to Natalie J. Forde, a PhD candidate at the University Medical Centre Gronigen (the Netherlands) and her colleagues. “Analysis of specific mainly frontal regions, previously implicated as potentially endophenotypic by functional magnetic resonance imaging analysis of the same cohort, revealed a significant effect of group in the right medial superior frontal gyrus and left middle frontal gyrus driven by reduced [organization] in [bipolar I] patients, compared with controls.”

Read the full study in Psychiatry Research: Neuroimaging (doi: 10.1016/j.pscychresns.2015.08.004).