Fronto-limbic disconnection in depressed patients with suicidal ideation: A resting-state functional connectivity study.
Suicidal ideation (SI) is highly prevalent and a known symptom of Major Depressive Disorder (MDD), but its underlying biological mechanisms are relatively unknown. Several studies linked suicidal ideation to dysfunctional brain circuits, specifically fronto-limbic connections. The purpose of this work was to investigate fronto-limbic disconnection in MDD patients with or without SI.



MDD patients with SI (SI, n=28) or without SI (NSI, n=20), identified by the Scale for Suicide Ideation and healthy controls (HCs, n=30) underwent resting-state functional MRI scanning. The functional properties of correlations in neural activity (intrinsic functional connectivity, iFC) of the rostral anterior cingulate cortex (rACC) were analyzed among the three groups. Furthermore, correlation analyses between iFC, SI severity and depression severity were performed.



We found that the SI group exhibited decreased iFC between the rACC, the orbitomedial prefrontal cortex and the right middle temporal pole compared to HCs and NSI groups. The NSI group showed decreased iFC between the rACC and the orbitomedial prefrontal cortex compared to HCs. In the SI group, iFC strength between the right rACC and the middle temporal pole positively correlated with SI severity.



Transdiagnostic and diagnosis-specific alterations of fronto-limbic iFC were found in MDD patients with or without SI. Disrupted fronto-limbic circuits may impact decision-making and emotional processing in SI. These results provide useful information about the pathophysiological mechanisms of MDD patients with SI.
Department of Psychiatry, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, PR China.
Lian
L
Du
Department of Psychiatry, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, PR China.
Jinkun
J
Zeng
Department of Psychiatry, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, PR China.
Huan
H
Liu
Department of Psychiatry, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, PR China.
Dejian
D
Tang
Department of Psychiatry, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, PR China.
Huaqing
H
Meng
Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, PR China. Electronic address: lymzhang70@aliyun.com.
Yongmei
Y
Li
Department of Psychiatry, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, PR China. Electronic address: fuyixiao2016@126.com.
Yixiao
Y
Fu
D000328:Adult; D003865:Major Depressive Disorder / Q000503:physiopathology* / Q000523:psychology; D004644:Emotions; D005260:Female; D006179:Gyrus Cinguli / Q000503:physiopathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D059020:Suicidal Ideation; D013702:Temporal Lobe / Q000503:physiopathology
Fronto-limbic disconnection; Intrinsic functional connectivity; Major depressive disorder; Rostral anterior cingulate cortex; Suicidal ideation