The case for using research on trait narcissism as a building block for understanding narcissistic personality disorder.

The empirical literature on narcissistic personality disorder (NPD) is quite sparse with only a small number of studies singularly devoted to this important construct. Of the published articles on NPD, the majority (approximately 80%) are either of a theoretical nature or present data from a case study perspective. There is, however, a thriving and growing literature on trait narcissism. In comparison to NPD, trait narcissism is viewed as a continuous construct in which no attempt is made to make dichotomous decisions of a clinical nature. Recent data suggest that research on trait narcissism is relevant to NPD as self-report scores are substantially correlated with the Diagnostic and Statistical Manual of Mental Disorders (4th ed., American Psychiatric Association, 1994) interviews of NPD and generate a five-factor model personality profile that is congruent with expert ratings of prototypical NPD. We review the literature on trait narcissism in relation to implicit and explicit aspects of self-esteem, self-presentation, decision making, relationships, work performance, and externalizing behavior (e.g., aggression). Ultimately, we argue that this literature might be used as a stepping stone toward the development of a better empirical understanding of NPD and its nomological network.