摘要目的:探究伴或不伴自杀意念的抑郁症患者风险决策行为及电生理差异。方法:2023年9月至2024年1月在南京脑科医院抑郁症专病门诊入组61例首发未治疗抑郁症患者，分为抑郁伴自杀意念组( n＝32)和抑郁不伴自杀意念组( n＝29)，同时在社区入组性别、年龄及受教育年限相匹配的健康对照( n＝36)。在进行爱荷华博弈任务(IGT)时，对被试进行事件相关电位(ERP)检测，记录反馈阶段所诱发的反馈相关负波(FRN)和P300的波幅和潜伏期。使用SPSS 26.0进行统计分析，采用双因素方差分析比较ERP指标的组间和组内差异，使用Spearman相关分析研究ERP指标与贝克自杀意念量表评分的相关性。 结果:(1)抑郁伴自杀意念组和抑郁不伴自杀意念组的IGT净得分均低于健康对照组(均 P<0.05)。(2)三组间不同反馈类型下FRN平均波幅比较，反馈类型主效应显著( F＝8.799， P＝0.004)，组别主效应显著( F＝6.396， P＝0.002)，交互作用显著( F＝4.200， P＝0.018)。在获益反馈下，抑郁伴自杀意念组和抑郁不伴自杀意念组的FRN平均波幅均低于健康对照组(均 P<0.05)。(3)三组间不同反馈类型下P300平均波幅比较，组别主效应( F＝15.719， P<0.001)和反馈类型主效应( F＝15.949， P＝0.001)均显著；组别和反馈类型交互作用不显著( F＝1.573， P＝0.213)。与抑郁不伴自杀意念组[(1.61± 0.22)μV]和健康对照组[(2.46± 0.20)μV]相比，抑郁伴自杀意念组[(0.85± 0.21)μV]P300平均波幅更低(均 P<0.05)。(4)抑郁症患者在损失和获益反馈下P300平均波幅与自杀意念均呈负相关(损失： r＝－0.435， P＝0.001；获益： r＝－0.318， P＝0.013)。 结论:伴和不伴自杀意念的抑郁症患者均存在风险决策缺陷，伴有自杀意念的抑郁症患者P300波幅的降低较无自杀意念抑郁症患者更加明显。P300平均波幅可能成为区分伴或不伴自杀意念抑郁症患者的电生理指标。

abstractsObjective: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.