Department of Psychiatry, National Clinical Research Center for Mental Disorders, The Second Xiangya Hospital of Central South University, Changsha 410011, Hunan, China.
Department of Psychiatry, National Clinical Research Center for Mental Disorders, The Second Xiangya Hospital of Central South University, Changsha 410011, Hunan, China.
J Affect Disord. 2022 Oct 1;314:263-270. doi: 10.1016/j.jad.2022.07.043. Epub 2022 Jul 22.
Suicidal ideation (SI) is a common symptom of major depressive disorder (MDD). Accumulating studies demonstrated that MDD with SI was associated with static alterations in brain activity and functional connectivity. However, given that brain is a highly dynamic system, the changes of brain dynamic patterns in MDD with SI remain unknown.
We included 60 MDD patients with SI (MDD-SI), 58 MDD patients without SI (MDD-NSI), and 58 healthy controls (HCs) who underwent resting-state functional magnetic resonance imaging. The sliding-window approach was used to calculate the dynamic fractional amplitude of low-frequency fluctuation (dfALFF) and dynamic degree centrality (dDC) to characterize the temporal dynamic regional activity and distant functional connectivity. We compared dfALFF and dDC across groups and further conducted correlations between abnormal dynamic metrics and the severity of suicidality.
In terms of the dynamic regional activity, MDD-SI showed decreased dfALFF in the left lingual gyrus and right middle occipital gyrus compared with MDD-NSI; in terms of the dynamic distant connectivity, MDD-SI showed decreased dDC in the right middle frontal gyrus compared with MDD-NSI. The decreased dDC in the right middle frontal gyrus was correlated with increased severity of suicidality.
The relatively small sample size.
We demonstrate the specific brain dynamic patterns of MDD-SI in regional activity and distant functional connectivity compared to MDD-NSI. Especially the decreased temporal variability of the distant connectivity in the middle frontal gyrus was associated with SI. These altered dynamic patterns may represent a potential neurobiological diathesis of SI in MDD.
自杀意念（SI）是重性抑郁障碍（MDD）的常见症状。越来越多的研究表明，伴 SI 的 MDD 与大脑活动和功能连接的静态改变有关。然而，由于大脑是一个高度动态的系统，伴 SI 的 MDD 中大脑动态模式的变化尚不清楚。
我们纳入了 60 例伴 SI 的 MDD 患者（MDD-SI）、58 例不伴 SI 的 MDD 患者（MDD-NSI）和 58 例健康对照者（HCs），他们接受了静息态功能磁共振成像。采用滑动窗口方法计算低频振幅分数（dfALFF）和动态度中心度（dDC）的动态变化，以描述时间动态区域活动和远距离功能连接。我们比较了三组之间的 dfALFF 和 dDC，并进一步分析了异常动态指标与 SI 严重程度之间的相关性。
在动态区域活动方面，与 MDD-NSI 相比，MDD-SI 患者的左侧舌回和右侧中枕叶的 dfALFF 降低；在动态远距离连接方面，与 MDD-NSI 相比，MDD-SI 患者的右侧额中回的 dDC 降低。右侧额中回的 dDC 降低与 SI 严重程度增加有关。
样本量相对较小。
与 MDD-NSI 相比，我们在区域活动和远距离功能连接方面显示出 MDD-SI 的特定大脑动态模式。特别是额中回远距离连接的时间变异性降低与 SI 有关。这些改变的动态模式可能代表 MDD 中 SI 的潜在神经生物学倾向。
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