Combined effects of neuroticism and extraversion: findings from a matched case control study of suicide in rural China.

Neuroticism and extraversion are potentially important markers of personality vulnerability to suicide. Whereas previous studies have examined these traits independently, we examined their combined effects. Data were collected from family members and/or friends of individuals 18 years or older who died by suicide (n = 64) in rural China and from age-, sex-, and geographically matched controls (n = 64). Personality was assessed with the NEO-Five Factor Inventory. Individuals with a personality style characterized by high neuroticism and low extraversion were at 3.07 (95% confidence interval [CI], 1.44-6.55) times greater risk for suicide than were individuals without this personality style; in contrast, a style characterized by low neuroticism and high extraversion conferred decreased suicide risk (odds ratio, 0.41; 95% CI, 1.44-6.55). We conclude that it may be clinically inadequate to conceptualize neuroticism, by itself, as a risk marker for suicide. However, when the negative affect characteristic of neuroticism is combined with the joylessness, pessimism, and hopelessness characteristic of low extraversion, risk for suicide is elevated.