Expanding the empirical taxonomy of mental disorders

• Main Author: Samph, Stephanie Pavlos
• Format: Dissertation
• Language: English
• Published: ProQuest Dissertations & Theses 01-01-2018
• Subjects: Clinical psychology; Personality psychology; Psychology
• ISBN: 0438284992; 9780438284999

Numerous problems, such as heterogeneity and comorbidity, exist within the current categorical classification system for mental disorders. Research instead supports a dimensional model that helps illustrate underlying commonalities between mental disorders. Most studies have focused on more common disorders such as MDD and GAD. Fewer have included OCD and eating disorders in analyses, and only one has included any somatic disorders. We aimed to further explore the location of uncommon mental disorders in an empirically supported taxonomy. We conducted CFAs with 15 candidate models based off of results from previous literature using a merged clinical and student sample of 463 participants who completed the PDSQ, a self-report scale designed to screen for DSM-IV disorders. Quality of fit varied little between these models and no clear frontrunner emerged, though they all approached an acceptable level of fit. Given the homogenous nature of our CFAs, we relied on EFAs to identify the best model for our data. A four-factor model resulted in the best fit when considering fit indices, parsimony, and previous literature. The model supports internalizing-fear, internalizing-distress, externalizing, and somatic/psychosis factors, with MDD, GAD, SP, AG, and PD aligning with past research. PTSD fell on internalizing-distress and OCD on internalizing-fear, also as expected, and BBED cross-loaded on internalizing and externalizing dimensions. Perhaps the most surprising result was that PSY did not load on its own factor, but rather with HYPCH and SOMD. This study provides further support for somatic disorders falling on a dimension separate from broader internalizing and externalizing spectra.