Neuroticism and extraversion as predictors of first-lifetime onsets of depression, anxiety, and suicidality in high-risk adolescents.

There is substantial evidence that personality traits, in particular neuroticism and extraversions predict depressive and anxiety episodes as well as suicidal ideation. However, little research has examined whether these traits predict the first onset of depressive and anxiety disorders and suicidal ideation. Moreover, the few studies to date have not adjusted for pre-existing subthreshold symptoms, assessed dimensionally. In this study, 144 adolescents were assessed at baseline, 9-, and 18-month follow-ups. Neuroticism and extraversion were assessed via self-report, and depressive and anxiety disorders and suicidal ideation were assessed with diagnostic interviews. Adjusting for age, sex, and baseline symptoms, logistic regression analyses showed that neuroticism predicted the first onset of depressive disorders. However, neither neuroticism nor extraversion predicted first onsets of anxiety disorders, extraversion did not predict depressive disorders, and neither trait predicted suicidal ideation onset or severity after adjusting for baseline symptoms. Neuroticism and extraversion may respectively predispose youth to depressive or anxiety disorders but not to suicidal ideation over and above pre-existing symptoms. Results have implications for the early identification of at-risk youth and prevention of depressive and anxiety disorders and suicidal ideation.