Impaired emotional response inhibition among adolescents with bipolar depression: evidence from event-related potentials and behavioral performance.

Abstract

Background: Impaired inhibition of inappropriate responses in the emotional context is a core feature in patients with bipolar disorder. However, there has been little research exploring the underlying mechanism of impaired response inhibition for emotional stimuli in adolescents with bipolar depression. To explore this issue, we employed event-related potentials (ERPs) to investigate the underlying neuroelectrophysiological mechanisms of inhibition of inappropriate emotional stimuli in adolescents with bipolar depression.

Methods: Twenty-five adolescents with bipolar depression and nineteen healthy controls completed an emotional Go/No-Go task during electroencephalography recording. Reaction time (RT), reaction time variability (RTV), discriminability, and response bias were measured as behavioral performance indicators. ERP components, theta-band oscillation and inter-trial coherence (ITC) were compared between the two groups.

Results: Behavioral performance analysis found that adolescents with bipolar depression showed smaller d' values, and larger RT and RTV, than healthy controls. Nogo-P3 amplitude was decreased in adolescents with bipolar depression in comparison with healthy controls. Theta-band oscillation and ITC for emotional stimuli were also reduced in adolescents with bipolar depression. Pearson correlation analysis showed there was a negative correlation between the Nogo-P3 amplitude induced by negative trials and RTV in adolescents with bipolar depression.

Conclusion: Our findings suggest that adolescents with bipolar depression exhibit abnormal response inhibition in the emotional context. Impaired attentional function and discrimination of emotional information are related to the failure of behavioral inhibition in negative emotional contexts, and attenuated P3 amplitude and theta-band oscillation could be an electrophysiological indicator for this impairment.