A multi-method evaluation of trait and state-sensitive impulsivity in relation to impulsiveness of suicide attempts and non-suicidal self-injury in an adolescent clinical sample.

Background: Understanding the heterogeneity of suicide attempts (SA), and non-suicidal self-injury (NSSI) - e.g., impulsiveness of these behaviors, as in the length of time between participants' thought of engaging in the relevant self-injurious behavior and acting on the thought - is an important step towards personalized intervention. Although impulsivity has been extensively studied in relation to SA and NSSI, much less work has evaluated impulsivity in relation to impulsiveness of these behaviors. This study assessed whether trait and state-sensitive impulsivity were associated with impulsiveness of SA and NSSI, respectively, in an adolescent inpatient sample. Methods: Adolescents (N = 146) were recruited from a psychiatric inpatient facility. Multiple regression models examined whether trait impulsivity via self-report (i.e., lack of premeditation, lack of perseverance, sensation-seeking, and negative urgency) and state-sensitive impulsivity via the stop-signal task (SST) were associated with impulsiveness of SA and NSSI, respectively. Results: Lack of premeditation was positively associated with impulsiveness of SA. Greater impulsivity, as reflected by worse impulse inhibition on the SST, was also positively related to impulsiveness of SA. Lack of premeditation and low sensation-seeking were associated with the impulsiveness of NSSI. Conclusion: These findings suggest that aspects of trait and state-sensitive impulsivity are differentially associated with impulsiveness of SA and NSSI. Collectively, these findings support the view that despite phenotypic overlap between these forms of self-injurious behaviors, important distinctions exist in their underlying correlates. They also support impulsiveness of these behaviors as a meaningfully manifestation of their heterogeneity.