Thesis (Ph. D.)--University of Texas at Austin, 2001. / Vita. Includes bibliographical references (leaves 139-149). Available also in a digital version from Dissertation Abstracts.

Thesis (Ph. D.)--University of Oklahoma, 1993. / Includes bibliographical references (leaves 176-181).

Thesis (Ph. D.)--University of Texas at Austin, 2001. / Vita. Includes bibliographical references (leaves 79-100). Available also in a digital version from Dissertation Abstracts.

published_or_final_version / Public Health / Master / Master of Public Health

Attention-deficit hyperactivity disorder (ADHD) is a developmental disorder of inattention, impulsivity and hyperactivity. It is the most commonly diagnosed psychosocial problems in childhood with continuing impact into adulthood. This systematic review aims to identify the role of food additives, specifically artificial food coloring, in ADHD and its symptoms. PubMed, Sciencdirect, Cochrane Library and Google Scholar databases (1991-April 2012) were searched, which was supplemented by manual searches of the reference lists. Seven randomized or quasicontrolled trials of elimination diet were summarized. Six of these studies showed artificial food coloring was positively associated with ADHD and its symptoms. This review provides some evidence that artificial food coloring plays a role in ADHD and its symptoms. However, the studies reviewed only showed behavioral improvement after eliminating certain type of artificial food coloring, which does not imply artificial food colorings cause ADHD. Additionally, small sample size, inconsistent definition of artificial food colouring, subjectively reported ADHD using various assessment tools, and possibly publication bias limit the generalizability of the findings. If causal, reducing the intake of artificial food coloring could provide an alternative treatment of ADHD in the future. Understanding the mechanism underlying the association may provide insights into the developmental origins of ADHD. / published_or_final_version / Public Health / Master / Master of Public Health

Despite many studies report a high prevalence of attention deficit hyperactivity disorder (ADHD) and reading disability (RD) among young delinquents, it is still not clear how the two disorders connect with delinquency. The main aim of this thesis was to understand the origin and progression of juvenile delinquency in groups of Chinese adolescents with ADHD, RD or comorbidity ADHD+RD. Three studies were conducted and reported in this thesis.In Study 1, executive functions(EF) and severity of delinquency were examined. Participants with ADHD only (n=29), RD only (n=24) and comorbidity ADHD+RD (n=35) were recruited from juvenile institutions in Hong Kong. Typically developing controls (n=29) were recruited from local schools. Assessment batteries on EF and self-reported questionnaire on delinquency were administered. Results of Study 1 showed that participants with ADHD were characterized with impairment in inhibition whereas participants with RD were characterized with impaired processing speed and visual memory. Compared to the pure groups, participants in the comorbid condition exhibited unique deficit in interference control. Importantly, the current study showed that the comorbid group had the highest severity of delinquency, and interference control; theunique deficit exhibited in the comorbid group was found to be a significant predictor of the severity of delinquency. In Study 2, psychosocial characteristics of the same juvenile sample of Study 1 were compared with typically developing control. A psychosocial questionnaire covering domains of academic orientation, parental relationships and victimization was administered. Results of Study 2 suggested that participants with RD wereassociated with negative effect across all psychosocial domains whereas participants with ADHD were mainly associated with poor academic orientation. Moreover, the comorbid group did not report having poorer psychosocial outcomes than the pure groups. The current data suggested that academic orientation was a significant factorpredicting onset of delinquency whereas direct victimization and poor father-child relationships marginally predicted severity of delinquency. In Study 3, the role of decision making at risk-taking events was investigated among the four study groups. Participants with ADHD only (n=37), RD only (n=35), comorbidity ADHD+RD (n=35), and control (n=36) were recruited from normal schools with varying levels of delinquency. A risk-taking simulated task, the Balloon Analogue Risk Task (BART) and a teacher-reported questionnaire on delinquency were administered. Results of Study 3 showed that participants with ADHD, despite their great risk-taking propensity, were motivated by the prospect of immediate feedback. In contrast, participants with RD were found to display normal risk-taking propensity, yet were less sensitive to punishment, suggesting a failure to switch between approach and avoidance behaviours for risky situations. Importantly, the comorbid group had the highest teacher-reported delinquency score, and exhibited the greatest risk taking and least sensitivity to punishment which further supported that comorbid condition might have a stronger impact on risk taking or even delinquency than pure groups. The present study increased knowledge about the unique delinquency pathways and important correlates associated with ADHD, RD and their comorbidity. The practical implications for intervention measures and early identification of at-risk adolescents with ADHD, RD and comorbidity were discussed. / published_or_final_version / Psychology / Doctoral / Doctor of Philosophy

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Current findings indicate that the symptom clusters of inattention and hyperactivity-impulsivity, the primary behavioral characteristics of AttentionDeficit/Hyperactivity Disorder (ADHD), serve as risk factors for reduced academic performance in postsecondary educational settings. The proposed investigation is designed to clarify the extent and mechanisms through which these associated symptoms clusters predict reduced academic performance in an undergraduate sample. This investigation tests four hypotheses: (a) ADHD symptoms predict inversely undergraduates' academic performance; (b) deficiencies in academic coping partially mediate the relationship between undergraduates' ADHD symptoms and academic performance; (c) deficiencies in undergraduates' executive functioning partially mediate the association between students' ADHD symptoms and their academic coping; and (d) the predictive association between students' ADHD symptoms and academic performance is more fully explained by their level of academic coping and executive functioning. To achieve these goals, 111 undergraduates from The University of Texas with variable levels of ADHD symptoms were recruited for participation in this study. Participants' academic performance (i.e., concurrent and cumulative semester grade point average, number of problem credit hours, and number of completed credit hours) will be compared to their level of self-reported ADHD symptoms (i.e., current and childhood ADHD symptoms). The hypothesized mediating effect of academic coping on this relationship was evaluated using two questionnaires of academic coping that separately assess students' general academic coping strategies and more specific academic coping behaviors. Further, the anticipated mediating effect of executive functioning on the relation between ADHD symptoms and academic coping was investigated using two neuropsychological tests of attentional control and planful problem solving. Results did not support the proposed model although several study hypotheses received partial support. A data-derived alternative explanatory model is presented and clinical implications are discussed.