Personality characteristics are linked to the course of mental disorders and to work functioning. This is of importance because such personality traits cannot be directly changed. This holds also true for personality disorders, which can be influenced by psychological interventions, coaching, or training (e.g. training of social skills, or work skills), but cannot be directly treated, or even cured, in clinical practice. The significance of enduring personality characteristics, be it accentuated personality traits which are quite common or real personality disorders, shows that there is a group of people in need of long-term supports in order to achieve vocationally. They found that the association between mental disorder and subsequent work impairment weakens or even disappears once personality characteristics were taken into account.