A Double-Blind, Placebo-Controlled Trial of Donepezil for the Treatment of Menopause-Related Cognitive Loss

A research primer for studies of cognitive changes across the menopause transition

There has been a proliferation of studies demonstrating important sex differences in cognitive aging and dementia, and with this an increased interest in the role of menopause and sex steroid hormones in women's brain health. Foundational longitudinal studies of cognitive changes from the premenopause to perimenopause stage have shown reliable declines in verbal memory, with variable findings in processing speed, attention/working memory and verbal fluency. Continued research is needed to advance understanding of the range of cognitive domains affected, the duration of cognitive changes, the generalizability of these changes across cultures, the factors that account for such changes and the factors that can improve cognition at this time. In this article, we briefly review and draw on findings from large longitudinal studies of cognitive changes across the menopause transition to inform the design of future studies on this topic. We focus on key issues such as objective versus subjective cognitive measures; cognitive domains and tests; staging menopause; study design; mediators of cognitive effects (including hormones and menopause symptoms); and consideration of key covariates. We suggest that a more uniform and evidence-based approach to the investigation of these issues can advance the quality of the science in menopause and cognition.

Menopause and cognitive complaints: are ovarian hormones linked with subjective cognitive decline?

Subjective cognitive decline (SCD) and the loss of ovarian hormones after menopause have been independently linked to later-life Alzheimer's disease (AD). The objective of this review was to determine whether menopause and the loss of ovarian hormones contribute to cognitive complaints and SCD in women. This would suggest that SCD at the menopausal transition might be an important marker of eventual cognitive decline and AD. We conducted a literature search using PubMed, PsycINFO and Web of Science in July 2020. All English-language studies assessing SCD and cognitive complaints with respect to menopause and ovarian hormones were included. A total of 19 studies were included. Studies found that cognitive complaints increased across the menopause transition and were associated with reductions in attention, verbal and working memory, and medial temporal lobe volume. Women taking estrogen-decreasing treatments also had increased cognitive complaints and reduced working memory and executive function. The current literature provides impetus for further research on whether menopause and the loss of ovarian hormones are associated with cognitive complaints and SCD. Clinicians may take particular note of cognitive complaints after menopause or ovarian hormone loss, as they might presage future cognitive decline.

Acute cognitive effects of donepezil in young, healthy volunteers

OBJECTIVE

The acute nootropic potential of donepezil in young healthy volunteers has not been adequately investigated mainly because in previous studies: (1) effects were assessed before peak-plasma concentration (Tmax) was reached; (2) only a few cognitive processes were assessed. Here we investigated a myriad of cognitive effects of augmentation of acetylcholine using an acute dose of donepezil in healthy adults at theoretical Tmax.

METHODS

This was a double-blind, placebo controlled, parallel group design study of cognitive effects of acute oral donepezil (5 mg). Subjects were tested twice after donepezil ingestion: 90 min (time that coincides with previous testing in the literature) and 210 min. (theoretical Tmax). The test battery included tasks that tap cognitive domains that are sensitive to acetylcholine manipulations.

RESULTS

At both testing times donepezil improved long-term recall of prose, objects recall, recall of spatial locations, and integration of objects with their locations, some effects having been related to self-reported mood enhancement. However, improvement of performance in the central executive measure (backward digit span) occurred only at Tmax.

CONCLUSION

Positive cognitive effects of acute donepezil can be observed in various cognitive domains including mood, but its full nootropic potential is more clearly found close to theoretical peak-plasma concentration.