Altered resting-state cerebral blood flow and functional connectivity mediate suicidal ideation in major depressive disorder

Abstract

The relationships among cerebral blood flow (CBF), functional connectivity (FC) and suicidal ideation (SI) in major depressive disorder (MDD) patients have remained elusive. In this study, we characterized the changes in CBF and FC among 175 individuals including 47 MDD without SI (MDDNSI), 59 MDD with SI (MDDSI), and 69 healthy control (HC) who underwent arterial spin labeling and resting-state functional MRI scans. Then the voxel-wise CBF, seed-based FC and partial correlation analyses were measured. Mediation analysis was carried out to reveal the effects of FC on the association between CBF and behavioral performances in both subgroups. Results showed that CBF was higher in MDDSI patients in the bilateral precuneus compared to HC and MDDNSI participants. MDDSI patients exhibited enhanced FC in the prefrontal-limbic system and decreased FC in the sensorimotor cortex (SMC) relative to MDDNSI patients. CBF and FC were significantly correlated with clinical variables. More importantly, exploratory mediation analyses identified that abnormal FC can mediate the association between regional CBF and behavioral performances. These results highlight the potential role of precuneus gyrus, prefrontal-limbic system as well as SMC in the process of suicide and provide new insights into the neural mechanism underlying suicide in MDD patients.

Ketamine treatment modulates habenular and nucleus accumbens static and dynamic functional connectivity in major depression

“…Decreases in Hb and somatomotor cortex FC were also found to be significantly associated with improvements in anhedonia. Prior imaging studies have reported altered FC of somatosensory and somatomotor networks correlate with depressive symptoms, including suicidality 108,109 . Preclinical studies also suggest Hb inhibition of dopamine neurons leads to suppression of body movements and to lowered motivation 110 .…”

Differences in resting‐state brain activity in first‐episode drug‐naïve major depressive disorder patients with and without suicidal ideation

“…The precuneus is considered as the core hub of DMN, which plays a crucial role in a diverse array of highly integrated functions including self‐referential processing, episodic memory retrieval and emotion regulation (Cunningham et al, 2017; Utevsky et al, 2014). Numerous neuroimaging studies demonstrated that the precuneus exhibited increased activation in patients with depression, which suggested that this abnormal activation might be closely associated with SI of MDD patients (Fan et al, 2022; Zhu et al, 2018). In a previous rs‐fMRI study, increased cerebral blood flow was observed in the bilateral precuneus of MDD patients with SI when compared with those without SI and HCs, which highlighted the important role of precuneus gyrus in MDD‐related SI (Fan et al, 2022).…”

“…Numerous neuroimaging studies demonstrated that the precuneus exhibited increased activation in patients with depression, which suggested that this abnormal activation might be closely associated with SI of MDD patients (Fan et al, 2022; Zhu et al, 2018). In a previous rs‐fMRI study, increased cerebral blood flow was observed in the bilateral precuneus of MDD patients with SI when compared with those without SI and HCs, which highlighted the important role of precuneus gyrus in MDD‐related SI (Fan et al, 2022). Disrupted white matter integrity of the bilateral precuneus might lead to abnormal brain activity within DMN, which might be related to the neuropathophysiological basis of SI (Long et al, 2018).…”

Cerebral neurovascular alterations in stable chronic obstructive pulmonary disease: a preliminary fMRI study

“…The arterial spin labeling (ASL), with good reliability and reproducibility ( Sigurdsson et al, 2015 ), has been validated against other perfusion methods, and has been utilized to measure CBF in many studies ( Lan et al, 2019 ; Thamm et al, 2019 ). Previous studies have shown that cerebral blood flow (CBF) coupled with cerebral metabolism and oxygen consumption ( Fan et al, 2022 ; Jezzard, Chappell & Okell, 2018 ; Liu & Brown, 2007 ). Furthermore, studies from Varkuti et al (2011) and Hagmann et al (2008) also identified positive correlation between cerebral structural hubs and CBF.…”