Menopause linked to loss of grey matter in the brain, study finds

Menopause is linked to grey matter loss in key brain regions, along with increased anxiety, depression and sleep problems, new research suggests.

The study also found that hormone replacement therapy (HRT) does not appear to mitigate these effects, though it can slow the decline in reaction times.

Grey matter is brain tissue that contains nerve cell bodies and helps process information, control movement and manage memory and emotions.

Dr Christelle Langley from the University of Cambridge department of psychiatry said: “Most women will go through menopause, and it can be a life-changing event, whether they take HRT or not.

“A healthy lifestyle – exercising, keeping active and eating a healthy diet, for example – is particularly important during this period to help mitigate some of its effects.

“We all need to be more sensitive to not only the physical, but also the mental health of women during menopause, however, and recognise when they are struggling.

“There should be no embarrassment in letting others know what you’re going through and asking for help.”

Researchers analysed data from UK Biobank of almost 125,000 women, who were classified into three categories: pre-menopause, post-menopause who have never used HRT, or post-menopause who have used HRT.

Participants answered questionnaires about their experience of the transition, self-reported mental health, sleep patterns and overall health.

Some took part in tests of cognition, including tests of memory and reaction times. Around 11,000 participants also underwent MRI scans, allowing the researchers to examine brain structure.

Post-menopausal women were more likely than those pre-menopause to have sought help from their GP or a psychiatrist for anxiety, nerves or depression, and to score more highly on questionnaires for symptoms of depression.

They were also more likely to have been prescribed antidepressants.

Although women in the HRT group had greater anxiety and depression compared with the non-HRT group, further analysis showed these differences were already present before the transition began.

The researchers suggest that in some cases, a woman’s GP may have prescribed HRT in anticipation of symptoms worsening.

Women post-menopause were more likely to report insomnia, get less sleep, and feel tired.

Those on HRT reported feeling the most tired of all three groups, even though there was no difference in sleep duration between these women and those not on the medication.

In both groups of women post-menopause, the researchers found significant reductions in grey matter volume.

These differences occurred particularly in the hippocampus, which is responsible for forming and storing memories; the entorhinal cortex, a gateway for passing information between the hippocampus and the rest of the brain; and the anterior cingulate cortex, which helps manage emotions, make decisions and focus attention.

Post-menopausal women who were not on HRT had slower reaction times than those yet to start the transition or who were on HRT.

However, there were no significant differences between the three groups when it came to memory tasks.

Dr Katharina Zühlsdorff from the department of psychology at the University of Cambridge said: “As we age, our reaction times tend to get slower – it’s just a part of the natural ageing process and it happens to both women and men.

“You can imagine being asked a question at a quiz – while you might still arrive at the correct answer as your younger self, younger people would no doubt get there much faster.

“Menopause seems to accelerate this process, but HRT appears to put the brakes on, slowing the ageing process slightly.”

Professor Barbara Sahakian, the study’s senior author from the department of psychiatry, added: “The brain regions where we saw these differences are ones that tend to be affected by Alzheimer’s disease.

“Menopause could make these women vulnerable further down the line.

“While not the whole story, it may help explain why we see almost twice as many cases of dementia in women than in men.”