Verbal fluency deficiencies and certain white matter abnormalities are potential biomarkers of bipolar disorder, according to Isabelle E. Bauer, Ph.D., and her associates.
The investigators found that patients with bipolar disorder performed worse on verbal fluency tests than did the healthy control group, and generated fewer S-words and animal names. Meanwhile, patients with bipolar disorder also showed large areas of altered fractional anisotropy, and mean and radial diffusivity (RD) values in several sections of the brain, including the superior and anterior corona radiata and the corpus callosum. Altered RD also was associated with reduced visuomotor capability and progressive demyelination.
“The reported impairment in verbal fluency and changes in [white matter] integrity in fiber tracts connecting to the internal capsule, the corona radiata, and the corpus callosum may serve as cognitive and neural markers of BD [bipolar disorder],” the investigators concluded.
Find the full study in the Journal of Psychiatric Research (2015;62:115-22 [doi: 10.1016/j.jpsychires.2015.01.008]).