A team of researchers from the Tohoku University Graduate School of Medicine and the Tokyo Metropolitan Institute of Medical Science has found that women who experience menopause before the age of 40 tend to have worse cognitive outcomes than those who reach menopause after the age of 50. This significant finding, published on 15 April 2025 in Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association, provides valuable insights for clinicians assessing dementia risk in female patients. Given the global prevalence of dementia among women, this research adds an essential piece to the puzzle of understanding how biological factors influence cognitive health.
The researchers chose to explore this connection because dementia disproportionately affects women, suggesting the presence of sex-specific risk factors. Early menopause has long been linked to a higher risk of late-life depression, a known contributor to dementia. However, direct evidence of the impact of early menopause on cognitive decline has been scarce. By focusing on this relationship, the study aims to clarify whether early menopause itself is a direct risk factor, independent of other contributing conditions like depression.
For the study, the team analysed data from the English Longitudinal Study of Ageing, which included 4,726 women and 4,286 men. Participants were classified into three menopausal age groups: early menopause, mid-range menopause, and late menopause. Cognitive function was assessed through tests measuring orientation, immediate and delayed recall, and verbal fluency, providing a comprehensive overview of mental performance. To ensure accurate results, the researchers adjusted for baseline modifiable dementia risk factors, such as cardiovascular health and lifestyle factors, which are known to influence cognitive decline.
Lead author Miharu Nakanishi from the Tohoku University Graduate School of Medicine emphasised the importance of isolating the impact of early menopause from other risk factors. “Since early menopause is associated with a higher risk of depression, which itself increases the risk of dementia, it was crucial to control for this factor to determine if early menopause directly contributes to cognitive decline,” Nakanishi explained. After these adjustments, the study found that women who reached menopause before 40 had significantly poorer cognitive outcomes at two-year follow-up assessments, including worse orientation and immediate and delayed recall. In contrast, women who reached menopause at or after 50 outperformed a comparison group of men, suggesting a potential protective effect associated with later menopause.
These findings suggest that women who experience early menopause may constitute a unique, sex-specific high-risk group for cognitive decline. While hormone replacement therapy (HRT), a standard treatment for menopausal symptoms, did not appear to influence cognitive outcomes in this study significantly, the results underscore the need for further research to explore the biological mechanisms linking female hormone levels to mental health. Understanding this connection could pave the way for targeted treatments aimed at delaying or preventing dementia in at-risk women.
More information: Miharu Nakanishi et al, Associations among age at menopause, depressive symptoms, and cognitive function, Alzheimers & Dementia. DOI: 10.1002/alz.70063
Journal information: Alzheimers & Dementia Provided by Tohoku University
