The effects of proton pump inhibitors on neuropsychological functioning.

The current study investigated the effects of proton pump inhibitor use and apolipoprotein ε4 carrier status on changes in neuropsychological functioning in healthy adults with familial risk factors for dementia. As part of the Wisconsin Registry for Alzheimer's Prevention study, 1,573 subjects were administered questionnaires on their medical history, gave blood samples, and were administered neuropsychological assessments during four visits over a 10-15 year period. Linear mixed models assessed if non-users, subjects who stopped, started, or consistently used proton pump inhibitors differed in changes in working memory, verbal memory, psychomotor speed, and cognitive flexibility. The models did not yield significant main effects for proton pump inhibitor use or interaction effects between proton pump inhibitor use and apolipoprotein ε4 carrier status on a decline in memory or processing speed. An interaction effect suggested stopping a proton pump inhibitor may be protective against declines in cognitive flexibility among non-carriers. Although stopping a proton pump inhibitor use may have mild protective effects on executive functioning for non-apolipoprotein ε4 carriers, proton pump inhibitor use was not associated with memory decline in a sample of subjects with familial risk factors for dementia.