The common cause, continuum/spectrum, and precursor models do not posit causal relations between personality and depression. In contrast, the predisposition model holds that personality plays a causal role in the onset of depression. However, the predisposition model overlaps with the precursor model in that both propose that the relevant traits are evident prior to the onset of depressive disorder. The major difference between these two accounts is that the precursor model assumes that personality and depression derive from the same set of etiological processes, but the predisposition model posits that the processes that underlie personality differ from those that lead to depression. Thus, the predisposition account implies a complex interplay among risk factors involving moderation and/or mediation, and this is what distinguishes it from the precursor model.3 The most common example—the diathesis-stress model—conceptualizes personality as the diathesis and stress as 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
