Psychometric examination and normative data for the narcissistic personality inventory 29 item version.

The Narcissistic Personality Inventory (NPI) is commonly used in empirical studies of narcissism. Few population-based studies have been published. Our aim was to do a confirmatory factor analysis (CFA) of the NPI 29 item version with a four-factor structure, in two population-based samples and in a patient sample, and present normative population-based data.