The Socio-emotional preference task in major depressive disorder: ERP evidence of social appraisal dysfunction

Research has demonstrated that some individuals with major depressive disorder (MDD) exhibit distorted social appraisal. This study aimed to explore the neuroelectrophysiological mechanisms of emotional processing bias in MDD and thus to understand their functional properties of social appraisal. Thirty-four MDD patients (18 Female/16 Male) and 34 healthy controls (HCs) (17 Female/17 Male) completed the Socio-emotional Preference Task (SePT). The behavioral and event-related potentials (ERP) data were analyzed. The behavioral results showed that the MDD group showed longer reaction times (RTs) to negative (P = 0.027, η2 = 0.072) and positive (P = 0.002, η2 = 0.140) stimuli compared to the HCs group, preferring negative stimuli (P = 0.018, η2 = 0.082). The ERP data indicated that the MDD group exhibited higher P200 amplitudes for negative (P = 0.028, η2 = 0.071) and neutral (P = 0.032, η2 = 0.068) stimuli compared to the HCs group. Additionally, they showed higher LPP amplitudes for negative (P = 0.004, η2 = 0.116) and positive (P = 0.025, η2 = 0.159) stimuli, with longer LPP latencies for negative stimuli (P = 0.039, η2 = 0.056). In the MDD group, multiple linear stepwise regression analysis showed that LPP amplitudes were positively correlated with RTs for positive stimuli (B = 0.009, P = 0.023) and negatively correlated with RTs for negative stimuli (B = -0.008, P = 0.008). Conversely, P200 amplitudes were negatively correlated with RTs for negative stimuli (B = -0.005, P = 0.050) but positively correlated with Hamilton Depression Rating Scale (HDRS-17) scores (B = 0.337, P = 0.032). Moreover, HDRS-17 scores positively correlated with the self-reported preference for negative stimuli (B = 6.345, P = 0.009) but negatively correlated with the self-reported preference for positive stimuli (B = − 205.181, P < 0.001). MDD prefer negative stimuli consistent with negative self-schema, allocating more resources from early (P200) to late (LPP) stages, suggesting a tendency for processing fixation. RTs to positive and negative stimuli showed an association with LPP amplitudes. Separately, a bias toward negative and away from positive stimuli correlating with the severity of depressive symptoms.