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.
Highlights
Suicide remains critically understudied despite being a public health crisis
This study is the first to use MEG to evaluate potential electrophysiological correlates of the implicit association between the self and death compared to the self and life as a potential objective marker of suicide risk
When comparing self-death/self-life associations directly, increased gamma power was found in amygdala and anterior insula for self-death categorizations compared with self-life categorizations
Summary
Suicide remains critically understudied despite being a public health crisis. While increased efforts have attempted to address this crisis, the suicide rate has risen by 30% over the past two decades [2]. Direct screening of suicidal thoughts and behaviors is of limited value as individuals may minimize reporting of Network Changes in Suicidal Associations their suicidal thoughts due to concerns about hospitalization. A critical need remains to identify objective markers of suicide risk and circumvent the limitations of self-report measures [3]. In the absence of such markers, suicide risk will remain inadequately assessed and treated. Understanding the neurobiology underlying suicidal thoughts could help develop targeted biological interventions (i.e., pharmacology, neurostimulation) that mitigate risk
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
