Differentiating suicide attempts and suicidal ideation using neural markers of emotion regulation

Background: Theories of suicide posit distinct etiological pathways for suicide attempts (SA) and suicidal ideation (SI) that are marked, in part, by disruptions in the ability to regulate reactions to threat/mutilation and interpersonally-relevant emotional stimuli. However, little research has specifically tested these associations. To address this gap, the present study extracted the Late Positive Potential (LPP) during an emotion regulation task to evaluate the independent associations that SA history and SI share with initial responsivity to, and regulation of, these distinct emotional contents. Methods: A clinical sample (N = 257) were recruited based on elevations in suicide risk factors. Participants completed a picture viewing and regulation task that included threat/mutilation, reward, and neutral images from the International Affective Picture System. Immediately prior to picture onset, participants were instructed to passively view the image, increase their emotional reaction to the image, or decrease their emotional reaction to the image. Results: Differential patterns of LPP amplitudes only emerged in the context of attempts to regulate emotional responses such that SA history predicted a superior ability to volitionally mitigate responses to threat/mutilation while SI was related to a worse ability to increase responses to reward. Effect sizes were in the small and small-to-medium range. Limitations: The present data were cross-sectional and included low trial counts. Conclusions: Taken together, these findings support existing theories of suicide suggesting that distinct mechanisms underlie suicidal thoughts and behaviors. Future research should seek to determine if these mechanisms may serve as a viable intervention targets.