Psychosocial correlates of the short term course of multiple sclerosis : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Psychology at Massey University
The present investigation developed and tested a theoretical model, which attempted to depict some of the complex relations among the psychosocial and physical health experiences of multiple sclerosis (MS) patients. The model is comprised of five constructs: psychological well-being, physical health status, stressors, disposition and social support. The pivotal aspect of the model is psychological well-being, through which all other factors exert their influence. The study consisted of a cross-sectional and a longitudinal phase. Participants in the cross-sectional phase were a convenience sample of 45 people diagnosed with MS. The longitudinal phase involved a subsample of 12 people for an additional six months. In the cross-sectional phase, one structured interview was conducted at the participant's home. The longitudinal participants completed (six) monthly structured interviews and physical examinations (by a physician) at the rehabilitation unit of the local hospital. Four strategies were used to analyze and interpret the data. Firstly, the cross-sectional data was analyzed using conventional between-subject regressions to examine aggregate relations at a single point in time. Secondly, the longitudinal data was analyzed using within-subject regressions to examine aggregate associations among changes in the variables. Thirdly, the longitudinal data was analyzed to examine intraindividual patterns. Lastly, a qualitative case study approach was used to interpret the factors preceding and following an exacerbation in one participant. Results of the cross-sectional analysis revealed that disposition and stressors were both related to psychological well-being but, unexpectedly, physical health status and social support had no associations with well-being. Stressors demonstrated an association with physical health status, and disposition was related to social support. The within-subject regressions suggested that disposition and social support moderate how changes in stressors impact on changes in psychological well-being, and how changes in emotional states impact on changes in physical health status. An association was found between stressors and physical health status. The intraindividual findings revealed that, in general, the variables within each major construct related to one another in line with conceptual expectations. When examining associations between constructs, aggregate findings, for the most part, could not be replicated at the individual level. The case study suggested that changes in stressors and psychological well-being precede and follow a relapse in the disease. Overall, the findings provided mixed support for the theoretical model. However, the quantitative findings, in combination with contextual information and observational evidence, contributed valuable insights regarding the MS illness process. During relatively stable periods of the disease, in general, psychological functioning does not appear to influence physical functioning, or vice versa. Persons with MS appear to use denial and other defence mechanisms to help them cope with their illness. The appropriateness of the methodological approaches used are discussed, and some of the difficulties in conducting research with MS patients are highlighted. Finally, limitations of the present study are noted and suggestions are made for future research.