Personality traits and the risk of incident (hypo)mania among subjects initially suffering from depressive and anxiety disorders in a 9-year cohort study.

•This large prospective cohort study had a follow-up of 9 years to study personality traits in relation to incident (hypo)mania within patients with depression and anxiety disorders.•Analysis on (hypo)mania symptoms (based on MDQ >7) revealed 233 new cases, with low agreeableness as the independent risk factor.•The analysis on (hypo)manic episodes (based on CIDI), with four follow-up measurements resulting in 31 new cases, consistently found that low agreeableness was the independent risk factor.