Levels of personality functioning and their association with clinical features and interpersonal functioning in patients with personality disorders.

Recently, the DSM-5 Personality and Personality Disorders Work Group has proposed a multiple level approach toward the classification and diagnosis of personality disorders (PDs), with the first level entailing a rating of impairments in levels of personality functioning. Although a number of measures that assess levels of personality functioning have been validated, given its prominent status in the DSM-5 proposal and contemporary theories of personality pathology, the Work Group has called for more research in this area (e.g., Bender, Morey, & Skodol, 2011). In response to this call, this study investigates the relationship between two major, well-validated dimensional measures of levels of personality functioning, that is, the Differentiation-Relatedness Scale (DR-S; Diamond, Blatt, Stayner, & Kaslow, 1991), as scored on the Object Relations Inventory (ORI; Blatt, Wein, Chevron, & Quinlan, 1979), and the Inventory of Personality Organization (IPO; Lenzenweger, Clarkin, Kernberg, & Foelsch, 2001), a self-report instrument, and their relationship with different measures of clinical and interpersonal functioning in 70 patients with a PD. First, results showed that higher levels of differentiation and relatedness of descriptions of self and significant others, and of the self in particular, were negatively related to indices of personality functioning as assessed by the IPO. Lower levels of personality functioning, as measured with both the DR-S and the IPO, were positively related to severity of depression, symptomatic distress, self-harm, and interpersonal problems. Finally, results showed that the DR-S and the IPO independently predicted clinical features and interpersonal functioning. Hence, this study lends further support for the concurrent and predictive validity of the DR-S and the IPO in assessing levels of personality functioning. However, more research concerning the validity of these measures in assessing levels of personality functioning is needed. Suggestions for further research are formulated.