Now, a new study shows that people who experience high anxiety at any point in their lives have a 48 percent higher risk of developing dementia. Dementia is a brain disease that impairs a person’s thinking, memory, and social ability.
Researchers examined 28 years of data from the Swedish Adoption Twin Study of Aging, which collects data on fraternal and identical twins who were raised together or apart from each other. The research involved 1,082 participants who completed in-person tests every three years, given comprehensive questionnaires and screened for dementia throughout the study.
Previous studies have looked into the connection between dementia and mental illness. This study was the first to find that anxiety was a risk factor for dementia regardless of whether the participant had depression.
“Anxiety, especially in older adults, has been relatively understudied compared to depression,” said lead study author Andrew Petkus, postdoctoral research associate of psychology at the University of Southern California. “Depression seems more evident in adulthood, but it’s usually episodic. Anxiety, though, tends to be a chronic lifelong problem, and that’s why people tend to write off anxiety as part of someone’s personality.”
The subjects self-reported various levels of anxiety. They were not diagnosed with psychiatric anxiety disorder as assessed by a psychiatrist in a one on one interview. Still, the twins who developed dementia had higher levels of anxiety throughout their lives. These are “frantic, frazzled people” who operate with a high level of anxiety on a daily basis, said co-author Margaret Gatz, a psychology professor at the University of Southern California.
The researchers also wanted to determine whether the self-reported levels of anxiety correlated to the risk of dementia. They found that people in the high anxiety group were 1.5 times more likely to develop dementia than those in the low anxiety group.
People with high levels of anxiety usually have higher levels of cortisol and other stress hormones. Chronic high levels of cortisol cause brain damage in areas including the hippocampus and the frontal lobe. The hippocampus handles memory and spatial navigation. The frontal lobe is responsible for high-level thinking.
The researchers now want to find if individuals who were treated for anxiety earlier in their lives show lower risks of dementia compared to those with untreated anxiety.
The study was published in the journal Alzheimer's & Dementia: The Journal of the Alzheimer's Association.
Sources: University of Southern California Press Room