Date of Award
2017
Document Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
Department
Psychology
Abstract
Certain personality disorders have been found to be present in the prodromal phase of schizophrenia at a higher rate than other personality disorders. The present study examines the incidence of personality disorder (PD) symptom endorsement and the rate of meeting diagnostic criteria for avoidant, paranoid, schizoid, and schizotypal personality disorders between a group of psychometric schizotypes (SZT) and their matched controls (MC) at two-year follow-up. This study is a continuation of an existing 10-year longitudinal study that found that there were significant differences between the two groups (schizotypes and controls) in the number of symptom endorsements and the rate of meeting diagnostic criteria for schizophrenia-spectrum personality disorders at baseline testing. It is hypothesized that, if schizophrenia is a developmental process, as development progresses, there will be a widening disparity between the schizotype group and the control group in the number of symptom endorsements and the rate of meeting diagnostic criteria for schizophrenia-spectrum personality disorders. Eighty-five SZT and 78 MC participants were administered the Personality Disorder Interview for DSM-IV-TR at both baseline testing and two-year follow-up to assess PD symptoms and diagnoses. Results indicate that individuals psychometrically identified to be at increased risk of developing schizophrenia endorse more symptoms of schizophrenia-spectrum personality disorders at two-year follow-up than matched controls. When baseline data were carried forward in lieu of missing follow-up data, results demonstrate that schizotypic individuals met diagnostic criteria for avoidant, paranoid, schizoid, and schizotypal personality disorders at a higher rate than controls. The present study supports the use of psychometric instruments to measure schizotypy rather than reliance on genetic vulnerability, and lends further support to the inclusion of avoidant personality disorder as a schizophrenia-spectrum personality disorder. The present study additionally supports the utility of the Chapman Psychosis Proneness Scales as a tool for predicting future mental health status. Finally, the present study adds to the growing body of literature supporting schizophrenia-spectrum personality disorders as endophenotypic indicators of schizophrenia.
Recommended Citation
Schuder, Kelly, "Personality Disorders As Endophenotypes Of Schizotypy In A Hypothetically Psychosis-Prone College Sample At Two Year Follow-Up" (2017). All-Inclusive List of Electronic Theses and Dissertations. 1686.
https://scholars.indianastate.edu/etds/1686