Thesis (Ph. D.)--University of California, San Diego, 2007. / Title from first page of PDF file (viewed November 7, 2007). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references.

Thesis (Ph. D.)--State University of New York at Binghamton, Department of Psychology, 2006. / Includes bibliographical references.

No description available.

Borderline personality disorder (BPD) and schizotypal personality disorder (SPD) are both characterized by inflexible and pervasive behavioral patterns that frequently lead to significant functional impairment. Although considerable research has been conducted on the biological and phenotypic aspects of these disorders, researching, diagnosing, and treating them remains a challenge, primarily due to the difficulties associated with the categorical nature of current diagnostic methods (Skodol and Bender, 2009) which, in turn, results in significant within-group heterogeneity and between-group co-occurrence. Given the relative paucity of research comparing aspects of these disorders with one another, the current study aimed to evaluate overlapping and differentiating aspects of BPD and SPD by examining the integrity of a brain region frequently implicated in both disorders, the cingulum. The current study used a 3T Siemens scanner to acquire structural and diffusion tensor imaging in age-, sex-, and education-matched groups of 28 adults with BPD, 32 adults with SPD, and 36 healthy control participants (HC). The anterior and posterior cingulate were manually traced on all participants and then volume and fractional anisotropy (FA) comparisons were conducted across the groups for the left and right anterior and posterior cingulate. Compared with HC, SPD patients had smaller relative cingulate white matter volume and BPD patients had marginally significantly smaller relative cingulate white matter volume, and the two patient groups did not differ from one another. With regard to FA findings, a spectrum pattern emerged, such that the BPD group had significantly lower FA in the posterior cingulum relative to controls, whereas the SPD group also had lower FA in this region but did not differ from HC. The BPD group had marginally lower FA in dorsal aspects of the anterior cingulum when compared with HC, and the SPD patients did not differ from HC or BPD individuals. In summary, the current study provides evidence of aberrant connectivity of the cingulum in BPD patients, but not SPD patients, compared with HC individuals. Consistent with prior work, overall results suggest potential involvement of cingulum in BPD symptomatology. / Psychology

Thesis (M.A.)--The University of North Carolina at Greensboro, 2008. / Directed by Thomas Kwapil; submitted to the Dept. of Psychology. Title from PDF t.p. (viewed Jan. 28, 2010). Includes bibliographical references (p. ).

Individuals diagnosed with schizotypal personality disorder (SPD) exhibit patterns of cognitive deficits, neuromotor disturbances, and behavior problems similar to individuals with schizophrenia, and thus SPD is thought to represent one point on the continuum of schizophrenia spectrum disorders (SSDs). Deficits in behavior, cognition, and motor functioning have been implicated as childhood precursors of SSDs and appear to also vary as a function of gender and family history of psychopathology. As such, studies of youth may help in further identification of individuals at risk for SSDs. The current study examined the prospective associations between problem behaviors, neuromotor and neurocognitive functioning, as well as SSD symptoms, at baseline and 2-year follow-up in youth meeting criteria for SPD, other personality disorders, or healthy controls. The neuromotor and neurocognitive measures were able to significantly predict SSD symptoms and behavior problems above and beyond baseline predictors. Overall, the findings provide further support for the role of subcortical motor centers operating together with prefrontal cortical areas in the regulation of higher-order cognitive functioning and in producing the psychiatric features of SSDs. Significant correlations between gender, family history of schizophrenia, and history of head injury with symptoms, behavior, cognition, and motor functioning were also found and highlight the importance of examining the effects of these variables in future investigations. In sum, the current study helped in identifying factors that predict the clinical course of schizotypy and may shed light on the disturbed neural circuitry underlying SSDs.

Ce travail de thèse s’inscrit dans une approche dimensionnelle de la psychopathologie et son objectif est d’apporter de nouvelles connaissances au champ de recherche qui considère l’existence d’un continuum entre schizophrénie et trouble bipolaire ainsi qu’entre traits de personnalité et pathologies. Afin d’explorer ces continuums, nous avons étudié, grâce à la méthode des potentiels évoqués cognitifs et l’étude de certaines de leurs composantes (N400, LPC), les processus neurocognitifs sous-tendant l’intégration d’un contexte sémantique et sémantico-émotionnel dans la schizophrénie, le trouble bipolaire, les traits de personnalité schizotypique et les traits de personnalité hypomaniaque. Premièrement, nous avons montré, que les patients schizophrènes stabilisés et les patients bipolaires euthymiques présentent des patterns de modulation de la N400 différents lors de tâches impliquant l’intégration d’un contexte sémantique ou sémantico-émotionnel. Néanmoins, ces résultats en défaveur de l’existence d’un continuum entre schizophrénie et trouble bipolaire pourraient être la conséquence de l’absence de symptomatologie commune entre nos deux échantillons de patients. Deuxièmement, les résultats des études portant sur la population pathologique et ceux des études portant sur la population générale présentant des traits de personnalité semblent en faveur de l’existence d’un continuum entre population générale et pathologie. En effet, les personnes présentant des traits de personnalité hypomaniaque présentent des similitudes dans les atteintes des processus neurocognitifs sous-tendant l’intégration d’un contexte sémantique et sémantico-émotionnel avec les patients bipolaires, et les personnes présentant des traits de personnalité schizotypique présentent des similitudes dans les atteintes des processus neurocognitifs sous-tendant l’intégration d’un contexte sémantico-émotionnel avec les patients schizophrènes. L’ensemble de nos résultats associés à ceux de la littérature semblent en faveur d’une approche dimensionnelle de la psychopathologie bipolaire et schizophrénique où les symptômes, davantage que le diagnostic, doivent être envisagés comme le point central du continuum. / This work is part of a dimensional approach of the psychopathology. Its goal is to bring new knowledge to the field of research that considers the existence of a continuum between schizophrenia and bipolar disorder as well as between personality traits and pathologies. In order to explore these continuums, we have studied, thanks to event-related potential method and the study of N400 and LPC components, neurocognitive processes involved in the integration of semantic and semantico-emotional context in schizophrenia, bipolar disorder, schizotypal personality traits and hypomanic personality traits. We have first demonstrated that stabilized schizophrenic patients and euthymic bipolar patients have different patterns of the N400 modulation during tasks involving semantic and semantico-emotional integration. However, these results against the existence of a continuum between schizophrenia and bipolar disorder could be due to the lack of common symptoms in both samples. Secondly, the results of our studies dealing with clinical population and those dealing with general population with personality traits seem to be in favor to the existence of a continuum between general population and pathology. As a matter of fact individuals with hypomanic personality traits have similitude with bipolar patients in disturbance in neurocognitive processes involved in the integration of semantic and semantico-emotional context. Furthermore, individuals with schizotypal personality traits have common difficulties with schizophrenic patients in neurocognitive processes involved in semantico-emotional context integration. The results of our investigation, combined with those in the literature, are in favor of a dimensional approach of schizophrenic and bipolar psychopathology. And this approach is more about considering the symptoms as the central point of the continuum rather than the diagnostic.