Background Metabolic syndrome refers to a cluster of metabolic dysfunctions denoting a high risk of developing cardiovascular disease (CVD) and diabetes. The key risk factors include insulin resistance and obesity. In recent decades psychological factors, including Type A personality, Type D personality, anxiety, and depression, have been found to be additional risk factors of metabolic syndrome. As people‘s behaviours and personalities are often influenced by cultural values, it would seem to be necessary to examine the associations between Type A and Type D personalities and metabolic syndrome within the context of culture. This study specifically examines the issue in the context of Chinese culture. In addition, people with Type A personality who tend to feel impatience or time urgency, anger or hostility, and competitiveness, were reported to be positively associated with anxiety. People with Type D personality who would easily have negative affectivity and social inhibition were reported to be positively associated with anxiety as well as depression. Therefore, anxiety or depression might have an effect on the associations between Type A and Type D personalities. However, to my best knowledge, no previous studies have examined the associations among Type A and Type D personalities, metabolic syndrome, and anxiety/depression. Objective This study examines associations among Type A and Type D personalities, metabolic syndrome, and anxiety/depression. It includes: 1) validating the Chinese versions of the Type A personality scale (Adolescent/Adult Type A Behaviour Scale, AATABS-3) and Type D personality scale (DS-14); 2) assessing the associations between Type A and Type D personalities with metabolic syndrome; 3) investigating the associations between anxiety/depression and metabolic syndrome; 4) measuring the association between Type A personality and anxiety; 5) testing the association between Type D personality and anxiety, as well as depression; and 6) determining the associations among Type A and Type D personalities, metabolic syndrome, and anxiety/depression. Methods A cross-sectional questionnaire survey was conducted on a random community sample of 741 adults in Hong Kong recruited by cluster sampling. Participants meeting the screening criteria of metabolic syndrome were offered further physical examination for confirming the diagnosis. Results For the Chinese version AATABS-3 scale (revised-AATABS-3), exploratory factor analysis (EFA) produced an 11-item 3-factor solution. The three factors were: 1) impatience/time urgency; 2) hostility/anger; and 3) competitiveness. The revised-AATABS-3 scale showed satisfactory internal consistency (Cronbach‘s alpha = 0.74). For the Chinese version DS-14 scale (revised-DS-14), EFA provided a 10-item 2-factor solution. The two factors were: negative affectivity and social inhibition. The revised-DS-14 scale showed good internal consistency (Cronbach‘s alpha = 0.90). Gender differences appeared in the associations between Type A and Type D personalities and metabolic syndrome. In the total population and female participants, there were no significant associations between Type A personality and metabolic syndrome. However, male participants with Type A personality were positively associated with metabolic syndrome. In the total participants, there were no significant associations between Type D personality and metabolic syndrome. However, female participants with Type D personality were positively associated with metabolic syndrome; whereas male participants with Type D personality were negatively associated with metabolic syndrome. Anxiety affected the association between Type A personality and metabolic syndrome in males only, whereas it affected the association between Type D personality and metabolic syndrome both in females and males. Depression affected the association between Type D personality and metabolic syndrome both in females and males. Conclusion and Discussion The revised-AATABS-3 and revised-DS-14 scales showed satisfactory psychometric properties. They might be more convenient and acceptable than the original scales for measuring Type A and Type D personalities in future research. Since EFA was a preliminary method for scale validation, further validation studies for these two scales are needed, for examples, on concurrent and discriminant validity. Gender differences occurred in the associations between Type A and Type D personalities and metabolic syndrome. The key findings were: *Type A personality was a risk factor of metabolic syndrome in male participants. *Type D personality was a risk factor of metabolic syndrome in female participants, but it exhibited a protective effect for preventing metabolic syndrome in male participants. *Anxiety played a protective effect in the associations between Type A and Type D personalities and metabolic syndrome in male participants. *Depression had a protective effect on Type D personality for developing metabolic syndrome in female participants, and it reduced the protective effect of Type D personality for preventing metabolic syndrome in male participants. The results of this study may give directions to future studies pursuing further investigations on metabolic syndrome, particularly in regard to personality traits, lifestyles, mental health issues, and coping strategies in cultural and social contexts, as well as gender differences related to the endocrine system. / published_or_final_version / Social Work and Social Administration / Doctoral / Doctor of Philosophy

Alzheimer’s disease (AD) is a devastating neurodegenerative disease with growing prevalence in our society. Patients suffering from this debilitating disorder also develop neuropsychiatric symptoms. Depression is one of the most frequently conveyed comorbidity; moreover, depression is also a risk factor associated with AD development. There is a complex interplay between the neurobiology of depression and AD, but their concomitant disease mechanisms remain largely unknown. Retraction of axons and dendrites has been reported to be a common occurrence in both illnesses, proposing the involvement of cytoskeletal dysfunction. Tau is a microtubule-associated protein that undergoes aberrant processing to form neurofibrillary tangles in neurodegenerative diseases such as AD. However, the role of tau in depression has not been well studied. The elucidation of pathophysiological mechanisms in depression is important to provide a more holistic understanding of AD pathogenesis. This study proposes the potential participation of tau phosphorylation in the pathogenesis of depression. In addition, this study will also investigate tau modifications under concomitant models of depression and AD. Primary cultures of hippocampal neurons were exposed to independent and cotreatments of corticosterone and β-amyloid (Aβ), to induce in vitro models of depression and AD, respectively. Sprague Dawley rats were subcutaneously injected with corticosterone for 14 days to induce an in vivo model of depression. Tau phosphorylation, aggregation and interaction with microtubules were examined. Results demonstrated that in both in vitro and in vivo models of corticosterone-induce depression, tau underwent increased phosphorylation at residues S396 and S404. Phosphorylated tau showed decreased interactions with microtubules and increased vulnerability to aggregate. Furthermore, the in vivo model of depression illustrated an altered localization of tau in the CA3 region of the hippocampus. Co-treatment of corticosterone and Aβ exacerbated aberrant tau phosphorylation and aggregation. In conclusion, this study provides evidence for the role of tau in depression, suggesting the occurrence of abnormal tau phosphorylation as an early event in the pathogenesis. Additionally, the pathophysiology of depression and AD may involve similar mechanisms in tau phosphorylation and aggregation. This study provides insight into the neurobiological linkages between depression and AD, and emphasizes the importance of tau-targeted interventions in neuropsychiatric disorders. / published_or_final_version / Anatomy / Master / Master of Philosophy

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Maternal depression is an important correlate of parental competence and child outcomes. The relationships among maternal depression and both parent and child outcome variables have been empirically validated. However, the mechanisms through which depression exerts its influence on maternal responsiveness have received less scrutiny. 137 mother-toddler dyads from a non-clinical sample were observed during a 20-minute interaction. Results showed that low child emotional expressiveness and behavioral assertiveness both result from and contribute to the unsupportive parenting of mothers high in depressive symptoms. The presence of both child effects and parent effects implies a bidirectional system of mother-child influence in the regulation of supportive interactions. / text

13-Cis-retinoic acid (13-cis-RA) is a synthetic retinoid and the active ingredient in the oral acne treatment Accutane. The medical literature has suggested that the use of 13-cis-RA for acne treatment can induce depression, but because acne itself can have a negative psychosocial impact on self esteem, whether or not 13-cis-RA can cause depression remains controversial. The purpose of this work was to examine whether chronic 13-cis-RA administration could induce depression-related behaviors in mice and to determine the impact 13-cis-RA has on regions of the brain thought to be associated with mood and depression. We found that chronic treatment of adolescent male mice with 13-cis-RA induced depression-related behaviors, as assessed by immobility in the tail suspension and forced swim tests. Although depression is a multifaceted disease in which many brain regions are involved, the regions that seem particularly vulnerable to the effects of 13-cis-RA are the serotonergic and hippocampal systems. In serotonergic cells in vitro, 13-cis-RA treatment increases protein levels of the serotonergic 5-HT[subscript 1A] autoreceptor and the serotonin reuptake transporter (SERT), two inhibitory components of serotonin (5-HT) signaling. In vivo, the median and dorsal raphe nuclei contain the main 5-HT producing cells. 13-Cis-RA uncoupled the functional connectivity of dorsal raphe nuclei from the hippocampal regions as measured by interregional correlations of cytochrome oxidase (CO) activity, a metabolic marker of neuronal activity. Decreased hippocampal neurogenesis is thought to occur in depression and is decreased by 13-cis-RA. 5-HT is also a known regulator of hippocampal neurogenesis. Uncoupling of the dorsal raphe nuclei from the regions of the hippocampus by 13-cis-RA treatment may be the cause of, or a result from, the decreased neurogenesis. Although retinoids are known regulators of apoptosis, the uncoupling of the dorsal raphe nuclei from the hippocampal regions was not due to serotonergic cell loss. Interestingly, 13-cis-RA treated animals with the lowest CO activity in the dentate gyrus have the highest immobility in the tail suspension and forced swim tests. Ultimately, the effects of 13-cis-RA on the serotonergic and hippocampal systems might be inducing depression-related behaviors. / text

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published_or_final_version / Psychology / Doctoral / Doctor of Philosophy

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