We know that certain mental illnesses and risk of dementia are linked. Depression, for one, and dementia have a well-established link—both after diagnosis and potentially leading up to it. Studies show that adults over 50 with depression are up to 65 percent more likely to develop Alzheimer’s disease. But can other mental illnesses, or symptoms of depression like anxiety, also shed light on who might be more likely to develop Alzheimer’s? That’s what researchers led by the Alzheimer’s Society were trying to answer in a new study that has linked moderate to severe anxiety in mid-life to dementia in later life.
The research team looked at four different high-quality studies of almost 30,000 people to find the connection. While they could not calculate exactly how much anxiety may increase dementia risk, since the four studies measured risk differently, their findings bolstered previous studies that show anxiety raises the risk of mild cognitive impairment, which is often the first sign of Alzheimer’s.
Although this study did not look at how treating mental illness could reduce the risk of dementia (and scientists have said that certain drugs used to treat depression have been associated with a slightly increased risk), other studies have shown that treating depression could lessen the impact on dementia risk. Can the same be said for anxiety? We’re still not sure, according to study authors. While the study shows a link, scientists can’t say for sure whether mental illness is part of dementia, or if having mental illness raises the risk of dementia.
“Currently, we don’t know enough about anxiety to say whether it is an early sign of the changes in the brain seen in dementia, or if it independently puts people at greater risk of developing the condition,” said James Pickett, head of research at Alzheimer’s Society.
So, what can people with anxiety do to lower their risk? Scientists are still trying to figure that out, but we do know that keeping busy, exercising and being on the lookout for things like hearing loss, which can be isolating for older adults and lead to depression, can help with dementia risk. Meanwhile, scientists hope to continue to study mental illness and dementia in order to unlock how symptoms like anxiety might be tied to brain health.
“What we do know is that changes in the brain can begin more than 10 years before dementia symptoms emerge,” said Pickett. “As well as anxiety, there are other complex mental health issues that can be seen in the early stages of dementia, and we need further research to unpick the relationship between these. With 1 million people set to be living with dementia by 2021, understanding this devastating condition could not be more pressing.”
This study was published in the journal BMJ Open.