The Synergistic Effects of Neuroticism and Extraversion on Suicidal Ideation, Single Attempts, and Multiple Attempts in an Inpatient Sample.

The current study sought to investigate the differential risk/protective factors of neuroticism and extraversion among individuals with only suicide ideation, those with a single suicide attempt, and those with multiple attempts. We hypothesized that extraversion would moderate the relation between neuroticism and suicide attempts (single and multiple) but not ideation. Patients in a private facility (N = 3343) completed measures assessing suicide history and general personality traits. Four moderation analyses were conducted with extraversion moderating the relationship between neuroticism and suicide ideation, single attempt (compared to zero attempts), and multiple attempts (compared to zero attempts and to single attempts). Extraversion moderated neuroticism only when comparing individuals with multiple suicide attempts to those with no attempts. Individuals who were low in both neuroticism and extraversion had higher levels of attempts than individuals with low neuroticism and high extraversion, highlighting the importance of considering biological predispositions as risk factors for suicide.