Similarly, the predisposition model can be expanded to recognize personality change. This dynamic predisposition model (Ormel & de Jong, 1999, Ormel et al. 2001) acknowledges transactions between personality and the environment and integrates them with the environmental moderation and mediation mechanisms of the classic predisposition model. In the environmental moderation version of this account, negative life experiences influence not only depression onset but also levels of trait vulnerability (Middledorp et al. 2008). This increase in personality liability may then lead to additional life stress. If this vicious cycle is perpetuated unchecked, personality liability would continue to increase, and at some point, a negative life event could overwhelm coping capabilities and elicit a depressive disorder. Importantly, and in contrast to the dynamic precursor model, in this account maladaptive traits alone are not sufficient to cause depression, and an environmental trigger is necessary.
