a moderator that precipitates the onset of depressive disorder. Alternatively, stress may be a mediator, so that personality vulnerability leads to negative experiences (e.g., interpersonal rejection, job loss), which in turn increase the probability of a depressive episode. A second difference between these models is that the predisposition model does not assume any phenomenological links between personality traits and depressive symptoms. Consequently, the predisposing trait may not have any phenotypic similarity to depression. Thus, the two most critical sources of support for the predisposition model would involve demonstrating that individuals with the trait are at increased risk for subsequently developing depression, and that other variables play a role in mediating or moderating this transition.
