Citation

Ballard ED, Gilbert JR, Fields JS, Nugent AC, Zarate CA. Front. Psychiatry 2020; 11.

Copyright

(Copyright © 2020, Frontiers Media)

DOI

10.3389/fpsyt.2020.577628

PMID

unavailable

Abstract

Limited knowledge exists regarding the neurobiology of suicidal thoughts, given that there are currently no direct probes of the suicidal state. This pilot study used magnetoencephalography (MEG) to evaluate correlates of the implicit association between the self and death compared to the self and life as objective markers of suicide risk. Healthy volunteers (HVs; n=21) completed a modified version of the Suicide Implicit Association Task (S-IAT) during MEG scanning. Gamma power--which is considered a proxy measure of excitation-inhibition balance--was directly compared in the self-death/self-life contrast. As a proof-of-concept, the ability of dynamic causal modeling to categorize HVs versus four individuals with recent suicide crisis (SC) was evaluated. In HVs, enhanced gamma power in both amygdala and anterior insula were found for the self-death compared with self-life contrast. In addition, connectivity estimates between early visual cortex, anterior insula, and amygdala correctly categorized SC participants with 77% to 82% sensitivity and 80% to 85% specificity. These findings, which implicate network-level changes in salience network and amygdala connectivity in mediating suicidal associations, require further replication in larger samples. Direct probing of suicidal thoughts with the S-IAT may provide foundational markers of neural circuits associated with suicide risk. © Copyright © 2020 Ballard, Gilbert, Fields, Nugent and Zarate.

Language: en

Keywords

adult; human; suicide; female; male; pilot study; suicidal ideation; suicidal behavior; suicide ideation; controlled study; disease association; clinical article; sensitivity and specificity; brain depth stimulation; task performance; Article; correlational study; clinical evaluation; insula; nerve cell network; diagnostic test accuracy study; mortality rate; amygdala; functional connectivity; anterior insula; visual cortex; dynamic causal modeling; implicit association; magnetoencephalography; salience network