Deconstructing Individual Differences in Long-Term Personality Disorder and Trait Change

Converging lines of evidence suggest that personality pathology is comprised of shared and unique impairments. The current study leveraged a large clinical sample (N=505) and a person-centered statistical approach, ipsative change analysis, to decompose individuals’ multidimensional profiles at two time points into a metric which captures change in the elevation of the profile (i.e., impairment severity) and change in relationships between dimensions in the profile (i.e., stylistic symptom presentation). Results demonstrated that both severity and style change were predictors of overall pathology change, although the relative importance of these metrics was influenced by assessment method. Specifically, structured interview showed strong effects of severity change relative to style change, whereas self-report was less definitive. In addition, severity change was the stronger predictor of changes in psychosocial functioning. Results support earlier evidence of shared and unique factors in personality pathology while highlighting the influence of assessment method on models of pathology structure.