Altered affective processing in bipolar disorder: an fMRI study.

Background: Previous studies have reported that patients with bipolar disorder (BPD) exhibit altered emotional processing and regulation. However, results remain largely inconsistent across studies. The aim of the current study was to further examine affective processing in patients with bipolar disorder.

Methods: Twenty-three patients diagnosed with BPD (Type I) and 18 healthy matched controls completed a backward-masked affect paradigm while undergoing functional magnetic resonance imaging. Participants also completed a computerized, overt task of facial emotional discrimination after scanning.

Results: Results demonstrated altered affective processing of happy and fearful stimuli in bipolar participants in the amygdala, anterior cingulate cortex (ACC), and dorsolateral prefrontal cortex (DLPFC) relative to controls. BPD participants also displayed significant deficits in identifying fearful facial affect.

Limitations: This study has a moderate sample size, and the patients with BPD were significantly older than the healthy control participants; this did not appear to impact results, and although statistically significant, it is not likely biologically significant.

Conclusions: These findings may have implications for patients with BPD, as altered affective processing could result in deficits in reading social cues.