The Association Between Resting State Functional Connectivity and the Trait of Impulsivity and Suicidal Ideation in Young Depressed Patients With Suicide Attempts

Abstract

Suicide is a leading cause of death among youth and is strongly associated with major depressive disorder (MDD). However, the neurobiological underpinnings of suicidal behaviour and the identification of risk for suicide in young depressed patients are not yet well-understood. In this study, we used a seed-based correlation analysis to investigate the differences in resting-state functional connectivity (RSFC) in depressed youth with or without a history of suicide attempts and healthy controls (HCs). Suicidal attempters (ATT group, n = 35), non-suicide attempters (NAT group, n = 18), and HCs exhibited significantly different RSFC patterns with the left superior prefrontal gyrus (L-SFG) and left middle prefrontal gyrus (L-MFG) serving as the regions of interest (ROIs). The ATT group showed decreased RSFC of the left middle frontal gyrus with the left superior parietal gyrus compared to the NAT and HC groups. Decreased RSFC between the left superior frontal gyrus and the right anterior cingulate cortex (rACC) was found in the ATT group compared to the NAT and HC groups. Furthermore, the left prefrontal-parietal connectivity was associated with suicidal ideation and levels of impulsivity, but RSFC of the left prefrontal cortex with the rACC was correlated exclusively with impulsivity levels and was not related to suicidal ideation in the ATT group. Our results demonstrated that altered RSFC of the prefrontal-parietal and prefrontal-rACC regions was associated with suicide attempts in depressed youth, and state-related deficits in their interconnectivity may contribute to traits, such as cognitive impairments and impulsivity to facilitate suicidal acts. Our findings suggest that the neural correlates of suicidal behaviours might be dissociable from those related to the severity of current suicidal ideation. Neural circuits underlying suicide attempts differ from those that underlie suicidal ideation.

Keywords: depression; functional magnetic resonance imaging; impulsivity; resting-state functional connectivity; youth suicide.

Figure 1

The number of suicide attempts in 35 ATT patients (who had attempted suicide 1 to 6 months prior to the fMRI scan).

Figure 2

Group differences in RSFC analysis using L-MFG as seed of ROIs. (A) post hoc t-tests revealed that the ATT group demonstrated decreased RSFC between the L-MFG and L-SPG compared to the NAT group (FWE corrected, p < 0.05). (B) Compared to HC group, NAT group showed decreased RSFC of the L-MFG with the left insular cortex, as well as with the right inferior frontal grus and R-MFG (FWE corrected, p < 0.05). (C) Compared to the HC group, the ATT group showed decreased RSFC of the L-MFG with the left insular cortex and L-SPG, and increased RSFC between the L-MFG and R-MFG (FWE corrected, p < 0.05).

Figure 3

Group differences in RSFC analysis using L-SFG as seed of ROIs and the statistical maps showing post hoc t-test results of RSFC analysis among the three groups. (A) The map of seed region of interest (ROI): left superior frontal gyrus (L-SFG, Peak MNI: −33 63 −6). (B) ATT group vs. NAT group; (C) NAT group vs. HC group; (D) ATT group vs. HC group; Red and blue denote increased and decreased RSFC, respectively, and the colour bars indicate the t-value from post-hoc analysis between each pair of groups.

Figure 4

Correlation analysis between aberrant RSFC and the traits of suicide-related behaviour in ATT group. (A) The RSFC between the L-MFG and L-SPG was negatively associated with SSI scores (r = −0.4056, p = 0.0156) and BIS scores (r = −0.3498, p = 0.0394). (B) The RSFC of the L-SFG with the rACC was negatively correlated with BIS-11 scores (r = −0.3472, p = 0.0410), but it was not associated with the SSI total scores (r = −0.2602, p = 0.1312).