Recent research out of the U.K. looked into the link between anxiety and the onset of dementia later in life. The meta-analysis examined four large studies of about 30,000 subjects and concluded: “Clinically significant anxiety…
Recent research out of the U.K. looked into the link between anxiety and the onset of dementia later in life. The meta-analysis examined four large studies of about 30,000 subjects and concluded: “Clinically significant anxiety in midlife was associated with an increased risk of dementia over an interval of at least 10 years.”
The findings, published in the journal BMJ Open, suggest that midlife anxiety may be an independent risk factor for late-onset dementia. This is different from the anxiety that might represent the initial symptoms of dementia, the authors write. However, they admit the link is only correlative; there is no proof that anxiety causes dementia, only that they tend to occur together.
So, the question remains: Is anxiety really a risk factor?
“We cannot determine from correlational studies whether moderate to severe anxiety in midlife causes dementia in later years, whether dementia in later years causes moderate to severe anxiety in midlife or whether both may be caused by other factors, such as depression, excessive stress, genetic factors common to both, etc.,” says Dr. Simon Rego, chief psychologist at Montefiore Medical Center/Albert Einstein College of Medicine in New York. “While there is a great deal of research supporting the notion that anxiety is common in patients with dementia, scientists are still trying to determine whether — and if so, how — anxiety significantly increases the risk of dementia.”
Stress — the Common Denominator
One widely held guess about this connection is the common denominator of stress. The study authors note that anxiety triggers an excessive stress response. That could have a damaging effect on brain health and lead to accelerated cognitive decline, Rego says. “There is some evidence showing a decline in learning memory with higher anxiety scores,” he adds.
That makes sense to Karen Lynn Cassiday, who is the owner and managing director of the Anxiety Treatment Center of Greater Chicago and a clinical assistant professor at the Rosalind Franklin University of Medicine and Sciences. Stress from any source, including anxiety disorder, causes inflammation. “Inflammation seems like a core variable in terms of many mental health disorders,” says Cassiday, who is a past president of the Anxiety and Depression Association of America. In fact, she thinks inflammation, which also results from a poor diet, environmental pollution, disruptions of the gut biome, poor sleep and a host of other problems, is the real cause here. “I’d put my money on, it is less on anxiety and more on the role of inflammation,” she says.
Another clue to this mystery is the time between the two disorders. “The most important finding in this analysis is that there are at least 10 years of separation between anxiety symptoms and a diagnosis of dementia,” says Dr. Charles B. Nemeroff, professor of psychiatry and director of the Institute for Early Life Adversity Research at Dell Medical School, the University of Texas–Austin “That suggests that anxiety wasn’t part of the dementia process. It wasn’t like the first sign of dementia was anxiety. This was 10 years out.”
Nevertheless, the study has some practical benefits. Depression has long been known to increase the risk of dementia by about twofold, says Nemeroff, an ADAA board member. Linking anxiety “is relatively novel,” he says. “This is important because, if we can identify people at risk for dementia, we can intercede earlier. Any predictive biomarker or clinical sign or symptom to predict risk is good news.”
If it is the stress caused by chronic feelings of severe anxiety that actually has a damaging effect on the brain and leads to dementia in later years, then learning skills to cope with anxiety and stress earlier may have a preventative effect, Rego says. “Evidence-based talk therapies for managing stress and anxiety, including cognitive behavioral therapy and mindfulness-based stress reduction techniques, are proven strategies for that,” he says.
Changing personal behaviors may help as well. “If people eat a vegan or paleo/ Mediterranean diet, they decrease the risk for anxiety disorders and improve overall health, and they also decrease the risk for Alzheimer’s,” Cassiday says. “We recommend all of our patients exercise, eat low on the food chain, try to do organic, avoid processed foods of any type and get enough sleep. Those things are intertwined, and they are powerful interventions.”
The study authors agree that “nonpharmacological therapies, including talking therapies, mindfulness-based interventions and meditation practices, that are known to reduce anxiety in midlife, could have a risk-reducing effect, although this is yet to be thoroughly researched.” It needs to be, Nemeroff says: “Anxiety disorder is highly treatable. If [these subjects] were treated for anxiety, would that have obviated or reduced their risk for dementia? It should be the subject of subsequent investigation.”