Objective:To explore behavioral and electrophysiological differences in risky decision-making between depressed patients with and without suicidal ideation.Methods:A total of 61 patients with first-episode untreated depression were enrolled in the depression clinic of Nanjing Brain Hospital from September 2023 to January 2024, which were divided into the suicidal ideation group( n=32) and the non-suicidal ideation group ( n=29).At the same time, healthy controls matched with sex, age and years of education were recruited from the community( n=36).The event-related potentials (ERP) of the participants were detected, and the amplitude and latency of feedback related negative waves (FRN) and P300 during the feedback phase under Iowa gambling task (IGT) were recorded. Statistical analysis was performed using SPSS 26.0 software.The inter-and intra-group differences of ERP indexes were compared using two-way ANOVA, and Spearman correlation analysis was conducted to examine the relationship between ERP indexes and scores of the Beck scale for suicidal ideation. Results:(1)Compared with healthy controls, depressed patients with and without suicidal ideation had both lower net scores in IGT (both P<0.05).(2)When comparing the mean FRN amplitude under different feedback types among the three groups, the main effect of feedback type ( F=8.799, P=0.004), the main effect of group ( F=6.396, P=0.002) and the interaction effect ( F=4.200, P=0.018)were all significant. Under gain feedback conditions, the mean FRN amplitude was lower in both depressed groups compared with healthy controls (both P<0.05). (3)The comparison of the mean P300 amplitude under different feedback types among the three groups showed that the main effect of group ( F=15.719, P<0.001) and the main effect of feedback type ( F=15.949, P=0.001) were both significant, while the interaction effect between group and feedback type was not significant ( F=1.573, P=0.213). The group with suicidal ideation ((0.85±0.21) μV) had a smaller amplitude than both the non-suicidal ideation group ((1.61±0.22) μV) and healthy controls ((2.46±0.20) μV) (both P<0.05). (4)In depressed patients, P300 mean amplitude under both loss and gain feedback conditions were both negatively correlated with suicidal ideation (loss: r=-0.435, P=0.001; gain: r=-0.318, P=0.013). Conclusion:Depressed patients with and without suicidal ideation both exhibit impaired risk decision-making. The decrease of P300 mean amplitude is more significant in depressed patients with suicidal ideation than those without suicidal ideation.P300 mean amplitude may serve as an electrophysiological marker to differentiate depressed patients with suicidal ideation and those without suicidal ideation.

Objective:To analyze the characteristics of electroencephalogram microstate parameters in first-episode drug-naive patients with major depressive disorder (MDD), so as to provide electrophysiological evidence for the pathogenesis and early diagnosis of MDD.Methods:Eighty-four first-episode, drug-naive outpatients diagnosed with MDD(MDD group) and 82 healthy controls(healthy group) participated in this study. Resting-state EEG data (5-6 min, with eyes closed) were recorded for all participants. Data preprocessing and microstate analysis were performed using MATLAB and EEGLAB software. Temporal parameters of resting-state brain network microstates were compared using SPSS 26.0.Results:This study identified four typical microstates: Class A microstate(auditory network), Class B microstate(visual network), Class C microstate(salient network), and Class D microstate(attention and control network). The coverage rate (0.16±0.06, 0.21±0.06), duration (67.72±7.07, 72.28±8.59), and incidence rate (2.38±0.68, 2.82±0.67) of microstate A in MDD group were significantly lower than those in healthy group ( F=22.115, 13.368, 18.779, all P<0.001), while the above indexes of microstate B in MDD group were significantly higher than those in healthy group(coverage rate: 0.24±0.07 vs 0.18±0.06, duration: 76.35±11.28 vs 69.46±8.52, incidence rat: 3.16±0.52 vs 2.52±0.57) ( F=41.287, 18.999, 52.245, all P<0.001). Additionally, the microstate D in MDD group showed significantly lower coverage rate(0.33±0.08, 0.36±0.08) and duration (89.66±15.38, 95.46±16.79)compared with healthy group( F=3.932, 4.215, both P<0.05). Notably, significant differences were observed in the transition probabilities between the following microstates: A→B, A→D, B→A, C→A, C→B, D→A and D→B (all P<0.05). Conclusion:First-episode drug-naive depressive patients are characterized by alterations in microstate A, microstate B, and microstate D, which may be the potential pathogenesis of MDD and may serve as electrophysiological indicators for early diagnosis of MDD.

Objective:To explore behavioral and electrophysiological differences in risky decision-making between depressed patients with and without suicidal ideation.Methods:A total of 61 patients with first-episode untreated depression were enrolled in the depression clinic of Nanjing Brain Hospital from September 2023 to January 2024, which were divided into the suicidal ideation group( n=32) and the non-suicidal ideation group ( n=29).At the same time, healthy controls matched with sex, age and years of education were recruited from the community( n=36).The event-related potentials (ERP) of the participants were detected, and the amplitude and latency of feedback related negative waves (FRN) and P300 during the feedback phase under Iowa gambling task (IGT) were recorded. Statistical analysis was performed using SPSS 26.0 software.The inter-and intra-group differences of ERP indexes were compared using two-way ANOVA, and Spearman correlation analysis was conducted to examine the relationship between ERP indexes and scores of the Beck scale for suicidal ideation. Results:(1)Compared with healthy controls, depressed patients with and without suicidal ideation had both lower net scores in IGT (both P<0.05).(2)When comparing the mean FRN amplitude under different feedback types among the three groups, the main effect of feedback type ( F=8.799, P=0.004), the main effect of group ( F=6.396, P=0.002) and the interaction effect ( F=4.200, P=0.018)were all significant. Under gain feedback conditions, the mean FRN amplitude was lower in both depressed groups compared with healthy controls (both P<0.05). (3)The comparison of the mean P300 amplitude under different feedback types among the three groups showed that the main effect of group ( F=15.719, P<0.001) and the main effect of feedback type ( F=15.949, P=0.001) were both significant, while the interaction effect between group and feedback type was not significant ( F=1.573, P=0.213). The group with suicidal ideation ((0.85±0.21) μV) had a smaller amplitude than both the non-suicidal ideation group ((1.61±0.22) μV) and healthy controls ((2.46±0.20) μV) (both P<0.05). (4)In depressed patients, P300 mean amplitude under both loss and gain feedback conditions were both negatively correlated with suicidal ideation (loss: r=-0.435, P=0.001; gain: r=-0.318, P=0.013). Conclusion:Depressed patients with and without suicidal ideation both exhibit impaired risk decision-making. The decrease of P300 mean amplitude is more significant in depressed patients with suicidal ideation than those without suicidal ideation.P300 mean amplitude may serve as an electrophysiological marker to differentiate depressed patients with suicidal ideation and those without suicidal ideation.

Objective:To analyze the characteristics of electroencephalogram microstate parameters in first-episode drug-naive patients with major depressive disorder (MDD), so as to provide electrophysiological evidence for the pathogenesis and early diagnosis of MDD.Methods:Eighty-four first-episode, drug-naive outpatients diagnosed with MDD(MDD group) and 82 healthy controls(healthy group) participated in this study. Resting-state EEG data (5-6 min, with eyes closed) were recorded for all participants. Data preprocessing and microstate analysis were performed using MATLAB and EEGLAB software. Temporal parameters of resting-state brain network microstates were compared using SPSS 26.0.Results:This study identified four typical microstates: Class A microstate(auditory network), Class B microstate(visual network), Class C microstate(salient network), and Class D microstate(attention and control network). The coverage rate (0.16±0.06, 0.21±0.06), duration (67.72±7.07, 72.28±8.59), and incidence rate (2.38±0.68, 2.82±0.67) of microstate A in MDD group were significantly lower than those in healthy group ( F=22.115, 13.368, 18.779, all P<0.001), while the above indexes of microstate B in MDD group were significantly higher than those in healthy group(coverage rate: 0.24±0.07 vs 0.18±0.06, duration: 76.35±11.28 vs 69.46±8.52, incidence rat: 3.16±0.52 vs 2.52±0.57) ( F=41.287, 18.999, 52.245, all P<0.001). Additionally, the microstate D in MDD group showed significantly lower coverage rate(0.33±0.08, 0.36±0.08) and duration (89.66±15.38, 95.46±16.79)compared with healthy group( F=3.932, 4.215, both P<0.05). Notably, significant differences were observed in the transition probabilities between the following microstates: A→B, A→D, B→A, C→A, C→B, D→A and D→B (all P<0.05). Conclusion:First-episode drug-naive depressive patients are characterized by alterations in microstate A, microstate B, and microstate D, which may be the potential pathogenesis of MDD and may serve as electrophysiological indicators for early diagnosis of MDD.