Brain fog is a common symptom of menopause. It refers to a collection of cognitive symptoms that can include some or all of the following: forgetfulness, finding words, difficulty remembering names or numbers, misplacing objects, and difficulty focusing and/or concentrating. Experts often describe it as a temporary decline in learning and remembering. Brain fog can affect 40-60% of women, and when it occurs, it is typically during the menopause transition. It is not a sign of dementia and does not mean that someone is more likely to get dementia.
When women with brain fog are evaluated with formal tests, they have a small decrease in cognitive processing speed and verbal episodic memory. Some women also have lower scores on tests that measure attention. Higher-order cognitive functions, such as strategic thinking and planning, are unaffected. Changes documented on testing are typically subtle, and most women still perform in the normal range. Women often perform better on the testing than they think. In one study, women in the menopause transition and menopause still performed better than men, although the difference between women and men lessened after menopause.
The good news is that brain fog reverses for most women, but there may be a small subgroup of women who are at risk for lasting changes in brain function. The risk factors for persistent issues are low socioeconomic status and a high-stress environment.
There is also data to show that some women experience difficulties with executive functioning during the menopause transition or with surgical menopause, but whether this is part of brain fog or a different entity isn’t known.
Brain fog is still somewhat of an enigma, in part because it’s a symptom that can describe many experiences, and it has historically been understudied. It may be more common for those who have had adverse childhood experiences (ACEs), and one hypothesis is this is due to an abnormal inflammatory response related to ACEs. Interestingly, in SWAN (the Study of Women’s Health Across the Nation), symptoms of menopause, specifically depression, anxiety, sleep disturbances, or hot flashes, did not seem to correlate with changes in cognitive testing. However, clinical studies show that when hot flashes are measured objectively with a monitor, they are associated with memory impairment on questionnaires. One reason for the discrepancy between SWAN and these other studies could be differences in study design. However, there may also be a difference between hot flashes that people report and hot flashes measured objectively with a device on the skin because, interestingly, when women report having a hot flash, it doesn’t always match up with an objectively measured physical experience. Whether a hot flash without measurable physical changes is just a milder hot flash and hence doesn’t affect the brain in the same way or is a different physiological phenomenon from a hot flash that can be objectively measured on the skin isn’t known. (There are a couple of cool studies that look at this, and I might dig one or two out to write about them because I think the biology is really fascinating).
There have been more studies detailing brain changes in menopause and what these changes might mean for brain fog. There are structural changes in the brain during the menopause transition, and women who experience more hot flashes appear to have more of these changes. For example, the volume of gray matter decreases in areas that are important for language, memory, and concentration, and there are also changes in how the brain is connected and uses glucose. But, it also appears that the brain may compensate for some of these changes. It’s important to stress that research here is in its infancy and that our brains are plastic and change in response to many experiences. For perspective, we also know that there are substantial changes in the brain structure after pregnancy. As time passes and research accumulates, we will hopefully understand what these changes mean.
A recent study published by Dr. Lisa Mosconi’s group showed an interesting finding: estrogen receptor density in the brain increases after menopause. One way