Identifying personality pathology associated with major depressive episodes: incremental validity of informant reports.

Major limitations are associated with the use of a single source of information to assess personality pathology. The construct validity of standardized interviews and informant reports on personality pathology has been established relative to other measures of personality pathology, but it is also important to consider these measures in relation to other constructs that should be related to personality pathology. One example is major depression. In this study, we evaluated whether less common clinical methods of assessment for measuring the same personality pathology constructs, including semistructured interviews and informant reports, demonstrate unique validity, using major depressive episode (MDE) as the external criterion. This analysis focuses on a representative, community-based sample of 1,437 participants and informants. We conducted a hierarchical logistic regression analysis and determined the order of entering the predictor variables based on likelihood of being used in a clinical setting as well as empirical recommendations. Each step of our regression model significantly increased our ability to predict lifetime MDE, including self, interviewer, and informant reports of personality pathology. Overall, these findings indicate that multiple sources of personality assessment provide unique information about the relationship between maladaptive personality traits and a history of MDE. Thus, semistructured diagnostic interviews and informant reports can be used as a resource to improve the validity of personality assessments.