Abstract
The aim of the present thesis was to evaluate the degree to which the personality trait neuroticism can be distinguished from internalizing psychopathology. The precise nature of the internalizing-neuroticism relationship, and the extent to which they share an underlying spectrum, has been subject of much debate (e.g., Ormel et al., 2013). Underpinning this investigation is the broader scientific endeavour to integrate and distinguish between normal personality traits and psychopathology, with recent theory suggesting that unique symptom dysfunction fundamentally distinguishes between them (Wright & Hopwood, 2021). A cross-sectional design was used and included both a New Zealand undergraduate university student sample (N = 463), and an international community sample (N = 450). Participants were administered a variety of self-report measures encapsulating the spectrum of emotional disorders, neuroticism, and impairment indices. Although the latent dimensions showed a similar pattern of association with impairment indices, Internalizing relative to Neuroticism tended to exhibit substantially larger correlations with most outcome variables. Furthermore, the modelled residuals representing what was unique about Internalizing, predicted substantial outcome variance beyond what was shared between Internalizing and Neuroticism. These findings support the perspective that internalizing can be distinguished from neuroticism by its unique link with dysfunction. A variety of important implications are discussed as they relate to theory and clinical assessment.