Personality also can inform treatment of depressive disorders post onset. In particular, traits can predict response to treatment. Substantial evidence has accumulated that individuals with lower N/NE have better treatment outcomes across modalities (Kennedy et al. 2005, Mulder 2002, Tang et al. 2009). Other Big Five traits have been studied less and their role is not yet certain. However, a recent large investigation of a combination intervention (medication plus psychotherapy) found that low N/NE and high conscientiousness predicted who would respond to treatment, and although high E/PE did not contribute directly, it amplified the effect of high conscientiousness (Quilty et al. 2008a). As discussed above, investigations of Cloninger’s traits have produced inconsistent results (Joyce et al. 2007, Kennedy et al. 2005, Mulder 2002). Few studies have examined personality facets, but preliminary evidence suggests that lower-order traits can add substantially to the prediction of treatment response (Bagby et al. 2008). Among clinical traits, self-criticism, but not dependency, was found to forecast poor treatment outcomes (Blatt et al. 1995). Furthermore, personality may be useful in matching patients to interventions. For instance, Bagby
