Why does my mother suffer from dementia?
Her parents did not. And they lived well into their 80s. Their bodies may have exhibited the frailty of age, but their minds remained as keenly incisive as they had always been. Their memories intact, they did not lose their words or their stories. They were all there.
Until they were not.
So, I puzzle: Why my mum? What awful catalyst carved the opportunity for this insidious thing to ooze in like mud, obliterating everything that was once clear?
Was it depression?
Experts tell us there's a relationship between depression and dementia. Some pose that depression might create an additional cognitive burden on the brain, so if a person begins to develop the "pathology" of dementia, those who have battled with depression battle harder for "brain space."
But depression isn't just about a blue mood. It hijacks physiology, too. It throws hormones into flux, endorphins diluted to useless insipidity, while cortisol—the stress hormone—floods the brain and might, scientists hypothesize, precipitate that devastating pathology.
Depression also disrupts appetite and energy levels; my mother existed for months on an unhealthy diet of tea and biscuits, scattered crumbs of an incriminating Hansel and Gretel trail that revealed her hiding places.
Is this what did it? Did the stillness imposed by her depression set her up for dementia? "I am inert," she told me once. If she had walked further, faster, and more frequently, would she have been safe? A lifetime of brisk walking, I read, could lead to the equivalent of a 16-year younger biological age by midlife.
How many years did Mum lose on account of a life interrupted by mental illness?
Or was it her stroke?
A stroke that stole her reading—pure alexia, meaning that the signaling system between the brain and eyes was broken, shattered into a million tiny pieces by a cerebral blow. It was hard to find where a sentence began and where it ended then. She could no longer decipher the alphabet. Did a loss of reading hasten cognitive unraveling?
You find yourself going round and round in circles, asking question after question, reading study after study, looking for answers. There must be a reason, you tell yourself. And you know—with the sting of shame—that this is not an entirely altruistic exercise: You become keenly aware of your cognitive health when you live with somebody whose own is coming undone. You know the odds.
Especially because, like Mum, I'm a woman. And women are twice as likely as men to succumb to dementia. Nearly two-thirds of the 5 million Americans living with Alzheimer's are women. Is this because we live longer—and in our dotage is a window of sinister opportunity flung open to create a crack for this to slink through? According to Alzheimer's Disease International, by the end of this decade, there will be 78 million people in the world with dementia; by 2050, there will be 140 million. Somebody in the world develops dementia every three seconds.