Background. Adults in their twenties appear to be at high risk for suicidal behaviors (SBs) and there is substantial evidence suggesting that certain personality traits may increase individual vulnerability to suicide.

Method. We investigated relationships of personality traits with two SBs in a cohort (n=1140) of 21- to 24-year-old adults, representative of the general population of Quebec. Subjects were assessed using a series of structured diagnostic and personality trait questionnaires. Multivariate logistic regression analyses were employed to identify personality trait correlates of suicide-attempt history and serious suicidal ideation in the context of other known risk factors, such as psychopathology and experiences of childhood sexual and physical abuse.

Results. Traits of conduct problems contributed to both suicide attempts [odds ratio (OR) 1·03, 95% confidence interval (CI) 1·01–1·06] and suicidal ideation (OR 1·04, 95% CI 1·02–1·07), while identity problems (OR 1·10, 95% CI 1·07–1·13) and gender-moderated impulsivity contributed exclusively to suicidal ideation.

Conclusions. Personality traits may make independent contributions to current suicidal ideation and previous suicide attempts in certain subgroups of suicidal individuals. In order to further explore their utility as markers of suicide risk and targets of intervention further investigation in clinical samples and other cultural and age groups is necessary.