CNN
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As if people with anxiety didn’t have enough to worry about, a new study adds to the list, suggesting that the disorder could nearly triple the risk of developing dementia years later.
The study, published Wednesday in the Journal of the American Geriatrics Society, is the first to examine the association between different levels of anxiety severity and dementia risk over time, as well as the effect of the timing of anxiety on that risk.
“Anxiety can now be considered a non-traditional risk factor for dementia,” Dr. Kay Khaing, lead author of the study and a specialist geriatrician at Hunter New England Health in Newcastle, Australia, said by email.
More than 55 million people worldwide suffer from dementia, a number that is expected to reach 139 million by 2050. As the disease is also a leading cause of death, researchers and healthcare professionals have focused their efforts on prevention, particularly by addressing risk factors such as anxiety or lifestyle habits.
Previous studies exploring the relationship between anxiety and dementia have largely measured participants’ anxiety at a single point in time, providing mixed findings – but the duration of a person’s anxiety is an important aspect worth considering, the authors argued.
The team studied 2,132 participants recruited from the Newcastle-based Hunter Community Study between December 2004 and December 2007. They were aged 60 to 81 years or older and, at the start of the study, provided health data such as whether they smoked or drank alcohol, or whether they had conditions such as high blood pressure or diabetes.
Three assessments, also called waves, were conducted five years apart. Researchers measured participants’ anxiety at the first and second assessments. Chronic anxiety was defined as anxiety at both the first and second waves. A person’s anxiety was considered resolved if they only experienced anxiety at the first wave. New-onset anxiety refers to anxiety identified only at the second wave.
Dementia was identified using International Statistical Classification of Diseases codes, or pharmacy benefit data showing the purchase of dementia medications, provided by the Australian Department of Health and Aged Care.
Ultimately, 64 participants developed dementia. Chronic and new-onset anxiety were associated with a nearly threefold increased risk of dementia from any cause, with an average delay in diagnosis of 10 years, the authors found.
Anxiety that resolved within the first five years was so weakly associated with increased risk that the odds were similar to those of people without anxiety — a finding that Dr. Glen R. Finney, a fellow of the American Academy of Neurology, called “a welcome addition to our knowledge of anxiety and dementia.” Finney, director of the Geisinger Memory and Cognition Program in Pennsylvania, was not involved in the study.
The results were also significantly influenced by participants under 70 years old.
“We have known for a long time that stress increases the risk of Alzheimer’s disease,” Dr. Rudolph Tanzi, director of the McCance Center for Brain Health at Massachusetts General Hospital in Boston, who was not involved in the study, said in an email. “This study is consistent with previous studies that therapy aimed at relieving anxiety can help reduce the risk of Alzheimer’s disease. But it is the size of this study that is particularly compelling.”
The authors of the latest research did not have information about what helped some participants overcome their anxiety.
The findings underscore “the importance of treating anxiety early and consistently,” said Dr. Joel Salinas, a neurologist and the founder and medical director of Isaac Health, a virtual and in-home clinical service for dementia and other brain health issues. Salinas was not involved in the research.
Stress and neurodegenerative diseases
The study has some limitations, including that participants’ anxiety measures were based on the four weeks before the assessments, the authors said. The team also lost 33% of participants who had higher anxiety at the start of the study; not knowing what ultimately happened to these people could underestimate the effect of anxiety on dementia.
“In the future,” Finney said, “it would be useful to follow up the results with a prospective study using cognitive and biological measures of stress hormones, inflammation and neurodegeneration, including for Alzheimer’s disease.”
The association between anxiety and dementia may be explained in part by the former’s link to vascular disease – a cause of dementia – and its harmful effects on cells, experts said.
Stress increases cortisol in the brain and inflammation, both of which kill nerve cells, said Tanzi, also director of the Genetics and Aging Research Unit at Massachusetts General Hospital.
Anxiety is also associated with the buildup of beta-amyloid, Khaing said, which is a hallmark sign of Alzheimer’s disease.
The disorder has also been associated with structural changes in the brain “such as atrophy of the brain and hippocampus, all processes that are also associated with dementia,” Khaing added. Atrophy refers to the wasting away of a tissue or organ, particularly as a result of cellular degeneration.
However, the study “may also suggest that anxiety may be an early manifestation of an underlying brain disease,” Salinas, an assistant professor of clinical neurology at NYU Langone Health, said by email. “A person’s early cognitive decline may contribute to their anxiety (for example, making mistakes or being embarrassed in social situations).”
At the start of the study, the authors excluded people who already had cognitive impairment, but they acknowledged that undetected decline is always possible.
Anxious people are also more likely to make unhealthy choices, such as eating a poor diet or smoking, the authors said.
Anxiety is a normal response to stressors, but if it’s excessive, “seek help,” Khaing said.
Talk to your doctor or mental health professional about your options, which may include lifestyle changes such as stress management, healthy eating, exercise and better sleep, all of which have a distinct influence on your risk of dementia, experts said. Important forms of treatment also include different types of therapy or antidepressant medications.
“But I recommend avoiding certain medications that alter the brain, including tricyclic antidepressants, benzodiazepines and strong antihistamines,” Finney said.
Cognitive behavioral therapy is the treatment of choice for many anxiety disorders. It involves uncovering “unhealthy thought patterns and how they may be driving self-defeating behaviors and beliefs,” according to the National Alliance on Mental Illness.
“Also try practicing meditation and limit your expectations of others and yourself when it comes to responding to emails, text messages and social media,” Tanzi said. “We also recommend avoiding people you don’t really like and interacting with those who have a positive effect… on your well-being.”
Tanzi pointed out that anxiety is the result of the “oldest, most primitive parts” of our brain being focused only on survival.
“It’s important to always try to be mindful and self-aware to see if your brain is intimidating you by overemphasizing these survival needs,” he said.