Dimensional models of personality pathology present a promising approach to the assessment of maladaptive personality in adults and children (eg. De Clercq, De Fruyt, & Widiger, 2009). In addition, recent findings show that some childhood maladaptive traits can be predictive of adulthood personality disorders (eg. Mervielde, De Clercq, De Fruyt, & Van Leeuwen, 2005). The Dimensional Personality Symptom Item Pool (DIPSI) is a questionnaire designed to measure maladaptive lower and higher order traits in children and adolescents. This study aims to examine the DIPSI’s scales and to replicate several previous findings of maladaptive trait patterns in children. The results indicate that the DIPSI’s lower and higher order trait scales are high in reliability and show many of the trait relationships suggested by previous literature. A successful outcome of this study serves as the first step towards establishing the DIPSI as a valid and useful measure of personality pathology in children.

Callous-unemotional (CU) traits are associated with severe and aggressive youth antisocial behavior (ASB) and are under consideration as a potential specifier for the diagnosis of Conduct Disorder in DSM-5 (Frick & Moffitt, 2010). This proposal demands more inquiry into the impact that CU traits have on behavioral subtypes of youth ASB. Normal-range personality traits, trait levels of anxiety, and hormonal stress reactivity (i.e., changes in the stress hormone, cortisol) are all factors that have been studied extensively in relation to ASB, but these relationships have not yet been considered in combination with CU traits. The purpose of the current set of studies was to examine the extent to which CU traits moderated links between these three factors and both overall and behavioral subtypes of ASB. In the first study, data were collected on children’s personality, CU traits, and three behavioral categories of ASB (physical aggression, relational aggression and non-violent rule-breaking behavior) for community (N = 742) and clinical (N = 183) samples of children. In the community sample, CU traits moderated links between Neuroticism, Extraversion, Agreeableness, Openness to Experience and ASB overall and externalizing behaviors, between Neuroticism, Extraversion and physical aggression and between Agreeableness, Extraversion and rule-breaking behaviors. In the clinical sample, CU traits moderated the link between Agreeableness and externalizing behaviors. In the second study, data were collected on children’s trait anxiety, CU traits, and the same three behavioral categories of ASB in a follow-up adolescent community sample (N = 145). Reactivity of cortisol in response to an unanticipated social stress test was also measured. Results revealed that CU traits moderated links between trait anxiety and ASB overall, externalizing behaviors and physical aggression. In females only, CU traits also moderated links between cortisol reactivity and ASB overall and externalizing behaviors. Combined, the results of these studies support the proposal that CU traits are a clinically useful diagnostic specifier with different implications for behavioral subtypes of ASB. Further, the present findings allow recommendations to be made for future research to further our understanding of the role CU traits play in CD, and to develop targeted interventions.

The ability to control one’s behaviour is a fundamental cognitive function subserved by the prefrontal cortex (PFC). Whereas the neural basis of inhibitory control is reasonably well-established, the possible influence of individual differences in personality on cortical activity associated with this ability remains largely unexplored. The present study obtained self-report ratings of Five-Factor Model personality traits from 42 healthy adults while hemodynamic oxygenation in the PFC was recorded during a Go/No-Go task. Results indicated that Neuroticism, Agreeableness and Openness to Experience were associated with attenuated activity in the lateral PFC, a region critical for emotion regulation and behavioural control, whereas Extraversion and Conscientiousness were associated with greater activation in these regions. Activity within the medial PFC, an area linked to task engagement and self-monitoring, shared a positive association with Agreeableness. These findings provide important insights into how neural systems supporting inhibitory control may be affected by individual differences in personality.

The ability to control one’s behaviour is a fundamental cognitive function subserved by the prefrontal cortex (PFC). Whereas the neural basis of inhibitory control is reasonably well-established, the possible influence of individual differences in personality on cortical activity associated with this ability remains largely unexplored. The present study obtained self-report ratings of Five-Factor Model personality traits from 42 healthy adults while hemodynamic oxygenation in the PFC was recorded during a Go/No-Go task. Results indicated that Neuroticism, Agreeableness and Openness to Experience were associated with attenuated activity in the lateral PFC, a region critical for emotion regulation and behavioural control, whereas Extraversion and Conscientiousness were associated with greater activation in these regions. Activity within the medial PFC, an area linked to task engagement and self-monitoring, shared a positive association with Agreeableness. These findings provide important insights into how neural systems supporting inhibitory control may be affected by individual differences in personality.

This thesis is divided into three texts. The first is a compendium, which situates the major themes of the second text (a fictitious novel) into a scholarly context and delves into the broader academic questions that arise from it regarding the treatment and care of people with special needs. Those themes are put into a context that enables special education teachers to expand thier notions about communicating with and understanding their autistic and special needs students. It not only examines my own autobiographical connection to the novel (by the fact that I have a sister with a combination of Down Syndrome and autism) but also extends the themes into a broader context, and looks at typical expectations in families with mentally handicapped members and the various methods and approaches of communicating with them. The third text elaborates on specific aspects of these themes in an endnote format.

This thesis is divided into three texts. The first is a compendium, which situates the major themes of the second text (a fictitious novel) into a scholarly context and delves into the broader academic questions that arise from it regarding the treatment and care of people with special needs. Those themes are put into a context that enables special education teachers to expand thier notions about communicating with and understanding their autistic and special needs students. It not only examines my own autobiographical connection to the novel (by the fact that I have a sister with a combination of Down Syndrome and autism) but also extends the themes into a broader context, and looks at typical expectations in families with mentally handicapped members and the various methods and approaches of communicating with them. The third text elaborates on specific aspects of these themes in an endnote format.

Chronic major depressive disorder (CMDD) is a common and debilitating illness. Its pathophysiology needs further elucidation, before more effective targeted treatments can be developed for this condition. To gain a better understanding of the psychobiology of CMDD, three interconnected studies were conducted that examined the interplay between chronic depression, cortisol responses, and personality. Study 1 examined cortisol responses to the Trier Social Stress Test (TSST) in CMDD participants (n=29) as compared to healthy controls (n=28). It was hypothesized that cortisol responses would be greater in the CMDD population. Results indicated that females with CMDD had increased cortisol output compared to female controls, a pattern consistent with the hypothesis. However, males with CMDD had decreased cortisol responses compared to male controls. These results suggest that cortisol responses to social stress are altered in those with CMDD; however, females and males experience fundamentally different changes. Study 2 examined moderating effects of personality on cortisol responses to the TSST in those with CMDD (n=51) as compared to healthy controls (n=57). It was hypothesized that higher neuroticism and/or lower extraversion would be associated with increased cortisol responses in CMDD participants. As hypothesized, lower extraversion was associated with increased cortisol reactivity in those with CMDD but not in healthy controls. However, no association was found between neuroticism and cortisol responses. These findings could support the notion that lower extraversion is a vulnerability marker for chronic depression and thus a possible target for treatment. Study 3, evaluated the cortisol awakening response (CAR) in CMDD participants (n=27) compared to healthy controls (n=30). It was hypothesized that such awakening responses would be more pronounced in the depressed population compared to controls. Contrary to expectation, no differences were found between the groups. However, lower extraversion was associated with a lower CAR in both CMDD and healthy controls, a finding that was not anticipated a priori. These interconnected studies suggest that examining relationships between depression, cortisol responses, and personality, can assist with identifying distinct psychobiological profiles in those with chronic depression. It is proposed that this strategy will improve the likelihood of developing more targeted treatments for this population.

Chronic major depressive disorder (CMDD) is a common and debilitating illness. Its pathophysiology needs further elucidation, before more effective targeted treatments can be developed for this condition. To gain a better understanding of the psychobiology of CMDD, three interconnected studies were conducted that examined the interplay between chronic depression, cortisol responses, and personality. Study 1 examined cortisol responses to the Trier Social Stress Test (TSST) in CMDD participants (n=29) as compared to healthy controls (n=28). It was hypothesized that cortisol responses would be greater in the CMDD population. Results indicated that females with CMDD had increased cortisol output compared to female controls, a pattern consistent with the hypothesis. However, males with CMDD had decreased cortisol responses compared to male controls. These results suggest that cortisol responses to social stress are altered in those with CMDD; however, females and males experience fundamentally different changes. Study 2 examined moderating effects of personality on cortisol responses to the TSST in those with CMDD (n=51) as compared to healthy controls (n=57). It was hypothesized that higher neuroticism and/or lower extraversion would be associated with increased cortisol responses in CMDD participants. As hypothesized, lower extraversion was associated with increased cortisol reactivity in those with CMDD but not in healthy controls. However, no association was found between neuroticism and cortisol responses. These findings could support the notion that lower extraversion is a vulnerability marker for chronic depression and thus a possible target for treatment. Study 3, evaluated the cortisol awakening response (CAR) in CMDD participants (n=27) compared to healthy controls (n=30). It was hypothesized that such awakening responses would be more pronounced in the depressed population compared to controls. Contrary to expectation, no differences were found between the groups. However, lower extraversion was associated with a lower CAR in both CMDD and healthy controls, a finding that was not anticipated a priori. These interconnected studies suggest that examining relationships between depression, cortisol responses, and personality, can assist with identifying distinct psychobiological profiles in those with chronic depression. It is proposed that this strategy will improve the likelihood of developing more targeted treatments for this population.

A growing body of literature is focusing on the influence of personality and emotion regulation on psychological health. Using archival data from an expressive writing project, the current study investigated the relationship between perfectionistic self-presentation and emotion regulation, and the influence of the interaction of these variables on psychological health among trauma survivors. The results indicate that both perfectionistic self-presentation and more difficulties in emotion regulation contribute to symptoms of distress. As well, higher levels of perfectionistic self-presentation were associated with more difficulties in emotion regulation. Further, emotion regulation mediated the relationship between perfectionistic self-presentation and psychological distress but not common physical complaints. More specifically, the non-acceptance subscale of emotion regulation was found to be significant in a test of multiple mediator model.

Background. Because there have been few studies examining resilience associated with postnatal (PN) depression, this study aimed at formulating and testing a theory-based model integrating both traditional resilience paradigms and non-traditional factors including existential beliefs about life, motherhood and religion. Method. Study hypotheses addressed prediction of PN depression, stress and resilience, and the confounding influence of negative affectivity (neuroticism). Study variables included PN depression (Edinburgh PN Depression Scale, EPDS), stress, neuroticism, self-esteem, mother's distress and ambivalence, purpose/meaning, religious belief, parity, age, marital and social status. They were assessed with standardized self-report instruments and, following a pilot, administered to a probability sample of women four months postpartum in a one-wave, community, postal survey. Because the overall response rate was so low (49%) only the Europeans were included in the study (N = 225; response-rate = 78%). Statistical hypothesis-testing included linear and logistical multivariate model-twilding techniques, and principal components analysis. Results. Sixteen percent scored in the major depression range (EPDS > 12), and 14% in the minor depression range. Depression was associated with stress, neuroticism, purpose/meaning, mother's distress and (marginally) religious belief, but not with self-esteem, mother's ambivalence, age, parity or social class. Although neuroticism was strongly associated with depression, and also overlapped with most psycho-social variables, nonetheless stress, purpose/meaning, and mother's distress maintained significant relationships with depression after neuroticism was statistically controlled. Stress was associated in part with the perception of losing one's freedom in the motherhood role (neuroticism controlled). When resilience was defined as high stress coupled with low depression, it was associated with low levels of neuroticism and mother's distress. When resilience was defined in terms of high levels of maternal satisfaction, it was associated with high purpose and low ambivalence. Principal components analyses revealed that (1) stress scores reflected two dimensions suggestive of distress and self-efficacy; and (2) depression, stress, neuroticism, self-esteem and purpose were markers for the same underlying component, whereas mother's distress and ambivalence were markers for another (unrelated) component. Conclusion. This study underlines the relevance of temperament, self-efficacy, self-transcendence, existential beliefs and motherhood-related cogniitions to the understanding of PN depression and stress. / Subscription resource available via Digital Dissertations only.