Zhang Shuang, Chen Jian-Mei, Kuang Li, Cao Jun, Zhang Han, Ai Ming, Wang Wo, Zhang Shu-Dong, Wang Su-Ya, Liu Shi-Jing, Fang Wei-Dong
Mental Health Center, University-Town Hospital of Chongqing Medical University, Chongqing, 401331, China.
Department of Psychiatry, First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, China.
BMC Psychiatry. 2016 Sep 29;16(1):337. doi: 10.1186/s12888-016-1047-7.
Suicide is the second leading cause of death among 15- to 29-year-olds in China, and 60 % of suicidal patients have a history of depression. Previous brain imaging studies have shown that depression and suicide may be associated with abnormal activity in default mode network (DMN) regions. However, no study has specifically investigated the relationship between DMN functional activity and suicidal behavior in depressed individuals. Therefore, in the present study, we directly investigated features of DMN brain activity in adolescent patients with histories of depression and attempted suicide.
A total of 35 sex- and age-matched suicidal depressed patients were compared with 18 non-suicidal depressed patients and 47 healthy controls. We explored functional activity changes in DMN regions that could be associated with suicidal behavior by comparing resting-state functional magnetic resonance imaging (rs-fMRI) signals using independent component analysis (ICA). Scores on six clinical scales that measure depression severity (Hamilton Depression Scale (HDRS) and Beck Depression Inventory (BDI)) and suicidal traits (Barratt Impulsiveness Scale (BIS-11), Suicide Attitude Questionnaire (SAQ), Beck Hopelessness Scale (BHS), and Scale for Suicide Ideation (SSI)) were compared in the three groups.
Compared with the healthy controls, all of the evaluated depressed patients showed increased functional connectivity in select DMN regions. The suicidal patients showed increased connectivity in the left cerebellum and decreased connectivity in the right posterior cingulate cortex (PCC), whereas the non-suicidal depressed patients showed increased connectivity in the left superior frontal gyrus, left lingual gyrus and right precuneus and decreased connectivity in the left cerebellum. Compared to the non-suicidal patients, the suicidal patients showed increased connectivity in the left cerebellum and the left lingual gyrus and decreased connectivity in the right precuneus. No differences in the scores of any clinical scales were found between the suicidal and non-suicidal depressed patients.
Collectively, our results highlight the importance of the DMN in the pathophysiology of depression and suggest that suicidal behavior in depressed adolescents may be related to abnormal functional connectivity in the DMN. In particular, abnormal connectivity in the PCC/precuneus and left cerebellum might be a predictor of suicidal behavior in depressed adolescent patients.
在中国，自杀是15至29岁人群中第二大死因，60%的自杀患者有抑郁症病史。既往脑成像研究表明，抑郁症和自杀可能与默认模式网络（DMN）区域的异常活动有关。然而，尚无研究专门调查DMN功能活动与抑郁个体自杀行为之间的关系。因此，在本研究中，我们直接调查了有抑郁症病史和自杀未遂史的青少年患者DMN脑活动的特征。
将35名性别和年龄匹配的自杀性抑郁症患者与18名非自杀性抑郁症患者及47名健康对照者进行比较。我们通过使用独立成分分析（ICA）比较静息态功能磁共振成像（rs-fMRI）信号，探索可能与自杀行为相关的DMN区域的功能活动变化。比较了三组在六个临床量表上的得分，这些量表用于测量抑郁严重程度（汉密尔顿抑郁量表（HDRS）和贝克抑郁量表（BDI））以及自杀特质（巴拉特冲动性量表（BIS-11）、自杀态度问卷（SAQ）、贝克绝望量表（BHS）和自杀意念量表（SSI））。
与健康对照者相比，所有评估的抑郁症患者在选定的DMN区域均表现出功能连接增加。自杀患者左侧小脑的连接增加，右侧后扣带回皮质（PCC）的连接减少，而非自杀性抑郁症患者左侧额上回、左侧舌回和右侧楔前叶的连接增加，左侧小脑的连接减少。与非自杀患者相比，自杀患者左侧小脑和左侧舌回的连接增加，右侧楔前叶的连接减少。自杀性和非自杀性抑郁症患者在任何临床量表得分上均未发现差异。
总体而言，我们的结果突出了DMN在抑郁症病理生理学中的重要性，并表明抑郁青少年的自杀行为可能与DMN中的异常功能连接有关。特别是，PCC/楔前叶和左侧小脑的异常连接可能是抑郁青少年患者自杀行为的一个预测指标。
