As illustrated by two articles that each investigate personality pathology and its correlates in adolescents—Aelterman et al. (
2010) on obsessive-compulsive personality disorder (OCPD) from a dimensional personality perspective, and Barry and Wallace (
2010) on indicators of pathological and normative development of youth narcissism—this commentary discusses four important assessment issues that have become more salient as the field considers a shift, through proposed changes in the
DSM, to an approach that incorporates trait dimensions as an important aspect of diagnosis: (1) the importance of using multiple information sources for valid personality/ PD assessment; (2) relations of personality traits to (mal)adaptivity in general and also with regard to (3) trait uni- versus bi-polarity; and (4) whether personality types have incremental predictive value beyond their component personality traits and related pathology. The article also discusses why research on childhood and adolescent personality/ PD is important in addressing these issues.