Hypomanic symptoms predict an increase in narcissistic and histrionic personality disorder features in suicidal young adults.

Consistent with the "scar hypothesis", according to which mood depression might impact personality, we examined the effect of unipolar and hypomanic mood disturbances on cluster B (i.e., narcissistic, histrionic, and borderline) personality disorder features. Data from 113 suicidal young adults were utilized, and cross-lagged associations between unipolar and hypomanic mood disturbances and cluster B personality disorder features were examined using manifest-variable structural equation modeling (SEM). Hypomanic symptoms predicted an increase in narcissistic and histrionic personality disorder features over the Time 1-Time 2 period, as well as an increase in narcissistic personality disorder features over the Time 1-Time 3 period. Unipolar depressive symptoms and borderline features were reciprocally and longitudinally associated, albeit at different time periods. The sample distinct features restrict generalization of the findings. An exclusive use of self-report measures might have contributed to shared method variance. Results are consistent with the notion that hypomanic symptoms increase narcissistic personality disorder tendencies.