The Collaborative Longitudinal Personality Disorders Study (CLPS): overview and implications.

The Collaborative Longitudinal Personality Disorders Study (CLPS; Gunderson et al., 2000) was developed to fill gaps in our understanding of the nature, course, and impact of personality disorders (PDs). Here, we review published findings to date, discuss their implications for current conceptualizations of PDs, and raise questions that warrant future consideration. We have found that PDs are more stable than major depressive disorder, but that meaningful improvements are possible and not uncommon. We have confirmed also that PDs constitute a significant public health problem, with respect to associated functional impairment, extensive treatment utilization, negative prognostic impact on major depressive disorder, and suicide risk. At the same time, we have demonstrated that dimensional models of PDs have clinical validity that categories do not, especially greater temporal stability. Furthermore, dimensional personality traits appear to be the foundation of behaviors described by many PD criteria. Taken together, our results lead us to hypothesize that PDs may be reconceptualized as hybrids of stable personality traits and intermittently expressed symptomatic behaviors.