Decreased response inhibition to sad faces during explicit and implicit tasks in females with depression: Evidence from an event-related potential study

- Depressed female patients showed dysfunctional response inhibition to both implicit and explicit sad facial expression.
- The selective impairment of response inhibition to sad faces occurred at behavior inhibition stage indexed by P3 component.
- P3 amplitudes were unrelated with clinical symptom, suggesting that decreased P3 maybe trait-like biomarker of depression.
- Depressed patients showed dysfunction in the rDLPFC which is related to cognitive control processing.

The present study aimed to investigate neural substrates of response inhibition to sad faces across explicit and implicit tasks in depressed female patients. Event-related potentials were obtained while participants performed modified explicit and implicit emotional go/no-go tasks. Compared to controls, depressed patients showed decreased discrimination accuracy and amplitudes of original and nogo-go difference waves at the P3 interval in response inhibition to sad faces during explicit and implicit tasks. P3 difference wave were positively correlated with discrimination accuracy and were independent of clinical assessment. The activation of right dorsal prefrontal cortex was larger for the implicit than for the explicit task in sad condition in health controls, but was similar for the two tasks in depressed patients. The present study indicated that selectively impairment in response inhibition to sad faces in depressed female patients occurred at the behavior inhibition stage across implicit and explicit tasks and may be a trait-like marker of depression. Longitudinal studies are required to determine whether decreased response inhibition to sad faces increases the risk for future depressive episodes so that appropriate treatment can be administered to patients.