Date of Award

2004

Publication Type

Doctoral Thesis

Degree Name

Ph.D.

Department

Psychology

Keywords

Psychology, Psychobiology.

Supervisor

Rourke, Byron

Rights

info:eu-repo/semantics/openAccess

Abstract

Objective. This pilot study aimed to advance our current understanding of the role of biological processes in the development of specific neuropsychiatric complications in HIV/AIDS. In particular, this project explored whether elevated systemic indicators of immune system (i.e., IL-6, TNF-alpha, and neopterin) and hypothalamic-pituitary adrenal axis (HPA) activation (i.e., cortisol) were associated with commonly reported clinical symptoms of cognitive impairment, fatigue, and depression. Method. Thirty-one HAART-naive adults (i.e., no past or current use of antiretroviral medications) adults with HIV infection completed subjective symptom questionnaires and neuropsychological tests. Blood samples were obtained and processed at three separate laboratories. One-tailed Spearman correlations were used to examine the relations between serum concentrations of immune and HPA factors, cognitive impairments (learning efficiency, attention/working memory, and psychomotor processing speed), and subjective symptoms (fatigue, depression, cognitive complaints, and general illnesses). Results. Neuropsychological impairment was not associated with the levels of biological markers. Depressive symptoms were, however, modestly associated with elevated IL-6 mRNA expression (rs = 0.40, p < .05) even after removing the influences of fatigue, total cognitive complaints, and illness symptoms (pr = 0.39, p < .05). Elevated serum neopterin was strongly associated with depressive symptoms in individuals taking antidepressants (rs = 0.83, p < .001), though the association was nullified in the group not taking any antidepressants (rs = -0.25, p > .05). More specifically, mean neopterin levels were higher in the depressed as compared with non-depressed group but only for those individuals taking antidepressants [F(1, 11) = 45.66, p < .0011. Conclusion. Increased subjective symptoms, especially depression, may be associated with elevated immune activation (i.e., higher levels of IL-6 mRNA and neopterin) in some individuals with HIV infection. While antidepressants may exert immunosuppressive effects in treatment-responsive individuals, treatment-resistant individuals may continue to have both elevated depressive symptoms and neopterin levels despite presumably therapeutic doses of antidepressants. Although replication in a larger sample is needed, these preliminary findings suggest that systemic biological markers (especially neopterin) may be useful in differentiating individuals at greater risk of developing chronic, debilitating depression. Implementation of alternative interventions may be necessary to alleviate depressive symptoms in this selective group and ultimately improve their quality of life.Dept. of Psychology. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2004 .W376. Source: Dissertation Abstracts International, Volume: 66-02, Section: B, page: 1214. Adviser: Byron Rourke. Thesis (Ph.D.)--University of Windsor (Canada), 2004.

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