An examination of prospective memory in multiple sclerosis: a theoretical approach using objective and subjective measures

Abstract

Objective: Prospective Memory (PM) is the ability to complete a task at some specific point in the future without constant rehearsal. PM is noteworthy for the impact it may have on everyday functioning in patient populations, but it is difficult to assess using objective neuropsychological tests, and thus self-report has commonly been used as a measure of PM function. One problem with this method of assessment is the lack of a theoretical basis for current measures, especially in light of the many recent advances toward a theory of PM. Individuals with Multiple Sclerosis (MS) are often high-functioning, but 50-72% suffer from some form of cognitive impairment, especially in cognitive domains thought to be essential to PM. The goals of the current study were to a) use a theoretically-based approach to examining PM in the MS population, using objective and subjective measures of PM; and b) assess the usefulness of a novel measure of subjective PM problems (the Prospective Memory Complaints Questionnaire (PMCQ)) in the MS population. Participants: Twenty-seven individuals with MS and twenty healthy controls, matched on distributions of gender, age, and education level. Methods: Participants underwent a series of 3 measures, which included 1) a novel self-report questionnaire (the PMCQ) assessing PM difficulties administered in an interview format; 2) a standardized, objective measure of PM (the MIST); and 3) a theoretically-based experimental PM task (the Complex Prospective Memory (CPM) task). Demographic variables, depression level, fatigue, quality of life, and level of MS symptom severity were also collected.Results: No significant between-group differences were found in performance on any of the objective and subjective measures of PM in the MS vs. HC groups. Within-groups analyses indicated that distinct factors in each group predicted objective PM (MIST) performance, and factors related to the utility of both the CPM task and the PMCQ (and the underlying theoretical model of each) were identified. Discussion: Overall, the current study demonstrated discrepant predictors of PM performance in MS and HCs, despite nonsignificant overall differences in performance when controlling for significant psychosocial and symptom severity factors. While much further research is needed to isolate the factors impacting PM performance in the MS population, the usefulness of a theoretical model of PM was demonstrated, as was the utility of examining PM using both performance-based and self-report measures.%%%%Ph.D., Clinical Psychology – Drexel University, 2012