PURPOSE: The present study aims to compare the performance on an everyday prospective memory test in persons with multiple sclerosis (MS) and healthy controls (HC) and to examine the association between prospective memory and executive function. It is hypothesized participants with MS will perform worse than HC on the time-based prospective memory test and that executive function deficits would be associated with impaired prospective memory—specifically, when the prospective memory task is more abstract (time-based cues) versus more concrete (event-based cues).

RATIONALE: Research has shown that 45%–60% of people with MS experience cognitive impairments in addition to physical symptoms, which may affect occupational performance. Memory is one of the most prevalent cognitive symptoms experienced by persons with MS. However, few studies have focused on examining prospective memory: the ability to remember to carry out a future task.

Prospective memory is a crucial cognitive process for successful occupational performance (e.g., remembering to take medication at specific time). Prospective memory is comprised of two components, time- and event-based prospective memory, that are assumed to require different amounts of executive processing. Therefore, to complete a prospective memory task while engaging in an ongoing activity, an individual must have intact executive functions.

DESIGN: A between-groups design was used to assess group differences. A correlations design was used to assess the associations between executive functions and prospective memory.

PARTICIPANTS: Twenty-eight participants with MS were recruited from advertisements, support groups, word of mouth, and the Kessler Foundation. Thirty HC were recruited from advertisements and by word of mouth. All recruitment and procedures were approved by the institutional review board and Health Insurance Portability and Accountability Act compliance boards. All participants were between ages 18 and 65 yr.

METHOD: During testing, each participant performed cognitive tests to assess prospective memory (Memory for Intentions Test; MIST) and executive functions (Delis–Kaplan Executive Function System; D–KEFS).

ANALYSIS: Group differences in prospective memory and executive functions were each analyzed by one-way analysis of variance. Correlation between prospective memory and executive functions was examined using Pearson correlation coefficients.

RESULTS: Participants with MS scored significantly worse on prospective memory (time-based tasks) compared with HC. However, no significant differences were observed on the event-based tasks. Additionally, significant correlations were observed between prospective memory time-based tasks and executive functions but not between D–KEFS and MIST event-based tasks.

DISCUSSION: The results supported the hypothesis that MS participants would perform worse on the prospective memory time based test compared to HC. Additionally, time based, but not the event based, prospective memory test was significantly associated with executive functions. Thus, the obtained results support the assumption that executive functions are related to prospective memory performance specifically when prospective memory demands are more abstract.

IMPACT STATEMENT: Prospective memory and executive functions are integral parts of everyday functioning at work and at home. Results of this study shed light on the link between the two and the need to thoroughly assess the interaction between task demands and cognitive abilities while providing occupational therapy services to persons with MS.