Perceived cognitive dysfunction in fibromyalgia (FM), "fibrofog," is common. Prior laboratory-based studies have limited our understanding of cognitive function in FM in daily life. The objective of this study was to explore levels of subjective and objective cognitive functioning and the association between subjective and objective aspects of cognition in people with and without FM in the lived environment.
Participants (n = 50 adults with FM; n = 50 adults without FM, matched for age, sex, and education) completed baseline measures of subjective and objective cognitive functioning (NIH Toolbox). They also completed ecological momentary assessments of cognitive clarity and speed and tests of processing speed and working memory, via a smart phone app, 5×/day for 8 days.
On baseline objective measures, the FM group demonstrated poorer cognitive functioning across 3 NIH Toolbox tests. There were no strong correlations between subjective and objective cognitive functioning in both the FM and control groups. In the lived environment, the FM group demonstrated poorer subjective cognition and objective working memory; groups did not differ on processing speed. Momentary ratings of subjective cognitive dysfunction were significantly related to changes in objective processing speed but not working memory, with no group differences.
Findings indicate worse laboratory-based and ambulatory subjective and objective cognitive function for those individuals with FM compared to those without FM. Similar associations between measures of subjective and objective cognitive functioning for the groups suggest that people with FM are not overstating cognitive difficulties. Future research examining contributors to ambulatory fibrofog is warranted.