Cognitive decline may be more rapid and Alzheimer's may develop earlier among women who experience menopause earlier, according to US scientists.

The team studied the health records of more than 2,500 older US women, looking for links between earlier menopause and brain volume shrinkage (atrophy). They found no link with brain volume, but did find that earlier menopause was linked with faster cognitive decline and earlier onset of Alzheimer's disease.

The findings suggest early menopause has long-term effects on brain aging, the team says, and it could be a way of identifying women in mid-life who are most at risk of dementia later for early intervention.