Impaired Conflict Detection Differentiates Suicide Attempters From Ideating Nonattempters: Evidence From Event-Related Potentials.

BACKGROUND: Existing research suggests that inhibitory control deficits may differentiate individuals who think about suicide from those who make a suicide attempt. However, no available research, to our knowledge, has examined whether suicidal behaviors are associated with disruptions in the ability to determine when inhibitory control is needed or the ability to engage inhibition of an inappropriate or maladaptive behavior. The current study utilized event-related potentials to investigate specific facets of inhibitory control and their associations with suicide attempt history among a heterogeneous clinical sample who reported current suicidal ideation. METHODS: Ideators with no past suicide attempts (n = 46) and those with a history of suicide attempts (n = 22) completed a complex go/no-go task. Raw waveforms and temporospatial principal components analysis were used to index conflict detection (i.e., Delta N2) and motor inhibition (i.e., Delta P3a). Behavioral performance indices were also examined. RESULTS: Suicide attempters exhibited deficits in detecting the need for inhibitory control, as indexed by a more positive Delta N2 factor, than did ideating nonattempters, even when accounting for psychiatric comorbidity and age. However, these results only emerged in the principal components analysis-derived latent factor. No differences in behavioral performance or Delta P3a amplitude emerged. CONCLUSIONS: A relative inability to detect when to inhibit a maladaptive behavior, but not the ability to engage motor inhibition to stop that behavior, may distinguish suicide ideators who make a suicide attempt from those who do not. However, future research with prospective designs are needed to determine how conflict detection deficits may contribute to the emergence or escalation of a suicidal crisis.