Dementia
The Link Between Mental Illness and Dementia
Mental illness, later in life, may be linked to dementia.
Posted November 12, 2023 Reviewed by Gary Drevitch
I think many women live with this fear in the back of our minds: Will I develop Alzheimer’s? As we age, we are especially cognizant of times when we misplace our keys only to have them turn up in unexpected places or when we can’t find the word we want to use for the umpteenth time. We are especially wary if there is a family history of the disease. My maternal grandfather was diagnosed with Alzheimer’s Disease (AD), only back then they referred to it as hardening of the arteries.
More women are diagnosed with Alzheimer’s than men, in part because we live longer. One study found that “incidence rates of any dementia and AD were greater in women than men, with any dementia rates diverging after age 85 and AD rates diverging around 80. This pattern is consistent with women's survival to older ages compared to men.”
The fear of developing dementia or Alzheimer’s can be especially concerning if we live alone, are unmarried, and have no children. (For more, see Apprehension About Aging Alone.) What will happen to us? Will we end up in some nursing home alone and forgotten? This is the stuff that nightmares are made of.
A new concern is emerging, though, as research examines the complex link between mental health and neurological disorders such as dementia and Alzheimer’s. The evidence suggests that having a mental illness is a risk factor for developing different forms of dementia, such as Alzheimers.
One study found that “individuals diagnosed with a mental disorder were more likely to develop dementia than those without a mental disorder diagnosis…Individuals diagnosed with psychotic, substance use, mood, neurotic, and all other mental disorders and who engaged in self-harm were all more likely than those without a mental disorder to be diagnosed with subsequent dementia,”
This research scares me as not only have I been diagnosed with major depressive disorder with psychotic features and struggled with self-harm, but in my twenties, I dealt with addiction to cocaine and Klonopin. I never had to go to rehab, as I was able to stop on my own, but I was using both substances steadily at different times in my life. From this research, it seems I’m on a straight path to dementia.
Another study considered age-at-onset of psychiatric illness and found that while “psychiatric disorders are associated with increased risk of subsequent dementia, severe and late‐onset depression showed stronger associations with dementia than earlier‐onset and mild‐to‐moderate depression.”
I’ve been dealing with depression for most of my life and I’ve maintained that while I need to be proactive about my mental health, there are no guarantees. I’ve experienced medications that were working and stopped working, external triggers, and internal activation of depressive episodes for reasons I could not identify.
I was wondering, Do I wake up one day and officially feel old? I remember when I had my stroke over five years ago and my most pronounced and prolonged deficit was my cognitive ability, I was so devastated, I sank into another severe depressive episode. Thank goodness with psychotherapy and working with a rehabilitative neuropsychologist, I was able to come out of the depression and regain my cognitive functioning.
As a social worker, a job that doesn’t require any physical labor, I plan on working into my seventies. Is that old? Will I start showing signs of dementia by then and, worst-case scenario, perhaps not even be aware of it? All these things have already run through my mind and now this new research makes my future feel even more uncertain.
Thanks for reading.