Identifying bipolar disorder and predicting its therapeutic response of cognitive impairment

Cognitive impairment has become a core feature of bipolar disorder (BD). However, the neurobiological mechanisms underlying BD and its cognitive deficits are still unclear. This study aims to explore potential biological mechanisms of BD cognitive impairment.

In this study, 96 first-episode and drug-naïve BD patients and 55 healthy controls (HCs) were recruited, and patients were followed up longitudinally for 24 weeks. All subjects complete rs-fMRI scans at baseline. The fALFF method was adopted to analyze rs-fMRI data. Partial correlation analysis was used to analyze changes in fALFF values with clinical variables or cognitive function.

The study found that the fALFF values in BD patients showed decreases in the right middle cingulate gyrus (MCG) compared to the HCs. The baseline fALFF values of the nonimproved cognitive function patients with BD (Non-Improved-Cog BD) showed decreases in the right MCG compared to HCs. moreover, the baseline fALFF values of the improved cognitive function patients with BD (Improved-Cog BD) showed decreases in right middle frontal gyrus (MFG) compared with that of the Non-Improved-Cog BD group. Increased fALFF values in the right MCG of BD group were negatively correlated with HAMD total scores, and increased fALFF values in the right MFG were negatively correlated with difference in visuospatial scores before and after of treatment. The abnormal spontaneous activity in the right MCG can serve as a biological marker for distinguishing between HCs and BD.

The changes in fALFF in the right MFG may be a biomarker for predicting the outcome of cognitive impairment in BD.