Document Type

Dissertation

Date of Degree

Summer 2011

Degree Name

PhD (Doctor of Philosophy)

Degree In

Psychological and Quantitative Foundations

First Advisor

Elizabeth M. Altmaier

Second Advisor

Leigh J. Beglilner

Abstract

Huntington disease (HD) is a genetically transmitted fatal neurodegenerative condition that currently has no cure. The symptoms of HD are manifested as cognitive declines, neuropsychiatric disturbances, and motor dysfunction. An autosomal dominant genetic defect is responsible for the onset of HD, which means that the children of an affected parent have a 50% chance of inheriting the disease. Predictive genetic testing for HD has been available since 1993, and a positive test result means that a person will develop HD with 100% certainty. People who have the HD-gene expansion, but have not yet manifested unequivocal motor signs, are said to be in the prodromal phase of HD. A number of studies have examined concerns about the utility of genetic testing and its negative psychological consequences for gene-expanded and non-expanded individuals (e.g., traumatization, suicidal ideation). Although research has understandably focused on the potential for distress, there has been some evidence suggesting that individuals may actually experience psychological growth related to a receiving a genetic test result (e.g., improved relationships, pursuing new opportunities). The aim of the present study was to understand the relationship between genetic testing, prodromal HD symptoms, and posttraumatic growth (PTG).

Participants were recruited through the multinational PREDICT-HD study (Jane Paulsen, PI) and they completed the Posttraumatic Growth Inventory (PTGI; Tedeschi & Calhoun, 1996) to assess permanent positive psychological change as a result of learning about their HD-gene status. The Symbol Digit Modalities Test (Smith, 1991), Unified Huntington's Disease Rating Scale Motor Exam (Huntington's Study Group, 1996), and the SCl-90-R Depression subscale (Derogatis, 1994) were also completed. A total of 82 gene-expanded patients and 37 non-expanded patients took part in this study.

Results revealed that gene-expanded and non-expanded individuals reported experiencing PTG, particularly in their appreciation for life and ability to relate to others. Gene-expanded and non-expanded participants did not differ in the amount of growth they reported, which indicated that the outcome of genetic testing was not related to how much growth people experienced. Age and gender were associated with PTG, with younger participants and women reporting the most growth. The amount of time elapsed since genetic testing, estimated proximity to a diagnosis of HD, and the clinical characteristics of prodromal HD were not related to PTG. In conclusion, people experience positive psychological change as result of genetic testing for HD. The findings of this study have important implications for future research and for mental health professionals assisting people through the genetic counseling process.

Keywords

genetic counseling, Huntington disease, posttraumatic growth, predictive genetic testing, psychological outcomes

Pages

xii, 175 pages

Bibliography

Includes bibliographical references (pages 151-175).

Copyright

Copyright 2011 Justin John Francis O'Rourke

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