Negative Affectivity and Disinhibition as Moderators of an Interpersonal Pathway to Suicidal Behavior in Borderline Personality Disorder

In this longitudinal study, we examined whether personality traits moderate the link between interpersonal dysfunction and suicidal behavior in a high-risk sample of 458 individuals diagnosed with borderline personality disorder. Participants were assessed annually for up to 30 years (mean number of follow-ups = 7.82). Using multilevel structural equation modeling, we examined (a) longitudinal, within-persons relationships among interpersonal dysfunction, suicidal ideation, and suicide attempts and (b) moderation of these relationships by negative affectivity and disinhibition. Negative affectivity predicted a stronger within-persons coupling between interpersonal dysfunction and suicidal ideation. Disinhibition predicted a stronger coupling between ideation and suicide attempts. Assessing negative affectivity and disinhibition in a treatment setting may guide clinician vigilance toward people at highest risk for interpersonally triggered suicidal behaviors.