The relationships between personality traits, dysfunctional schemas and personality disorder features

The overall aim of this thesis was to explore the relationships between personality traits, dysfunctional schemas and personality disorder (PD) features. Previous research has established that personality traits and dysfunctional schemas are associated with personality disorders (PDs). However, comparatively little research has examined the relationships between personality traits and dysfunctional schemas or explored whether dysfunctional schemas have incremental validity in the prediction of PD features over and above personality traits. Thus, three studies were conducted to understand PD features from an integrated perspective that incorporates some of the key elements from both trait and cognitive-behavioural theories of PDs. Study 1 ( = 313) and Study 2 ( = 269) investigated the relationships between personality traits, dysfunctional schemas and PD features in non-clinical analogue samples through the use of several self-report measures. Correlational analyses in Study 1 and Study 2 revealed that general personality traits from the Five-Factor Model (FFM) and maladaptive personality traits from the Schedule for Nonadaptive and Adaptive Personality (SNAP) model, respectively, were meaningfully correlated with: (a) dysfunctional schemas conceptualised as either early maladaptive schemas (EMSs) or dysfunctional PD beliefs; and (b) theoretically-relevant PD features. Further, correlational analyses in Study 1 revealed a large number of positive zeroorder correlations between EMSs, dysfunctional PD beliefs and PD features. However, partial correlations in Study 2 revealed that these zero-order correlations were substantially reduced and consequently more interpretable and theoreticallymeaningful when psychological distress and general PD symptomotology were statistically controlled. A series of hierarchical multiple regression analyses in Study 1 and Study 2 revealed that subsets of either FFM or SNAP traits, respectively, and subsequent subsets of dysfunctional schemas collectively accounted for a substantial amount of variance in PD features. Specifically, subsets of EMSs and PD-specific dysfunctional beliefs added incremental validity to the prediction of PD features over and above traits from either dimensional trait model. Of particular note, the hierarchical regression analyses in each study revealed that each PD syndrome was associated with unique a combination of both FFM or SNAP traits and dysfunctional schema predictors. It was argued that these unique combinations of dimensional