Treating Anxiety Could Reduce Dementia Risk

Over 55 million people globally are living with dementia, a figure that is expected to rise to 139 million by 2050.

As efficacious treatments for dementia are lacking, the scientific community is investigating different approaches to disease prevention. This requires the identification of risk factors – genetic or environmental – that might increase an individual’s likelihood of developing dementia.

A new study by researchers in Australia explored whether anxiety could be one such risk factor, discovering that chronic anxiety and new onset anxiety are associated with all-cause dementia risk in an Australian cohort. The research, led by Professor John Attia at the University of Newcastle, is published in the Journal of the American Geriatrics Society.

Anxiety and dementia risk – is there an association?

While published studies investigating the relationship between anxiety and dementia exist, they have typically measured anxiety at baseline, and have delivered “inconclusive reports”, the research team said: “This could be due to significant heterogeneity in the measurement of anxiety and dementia, the follow-up period and the characteristics of participants, such as age.” 

“Moreover, these studies did not address the persistence of anxiety (chronic vs. resolved vs. new onset) on dementia risk, which could also contribute to the inconclusive results,” they added.

Attia and colleagues hypothesized that the persistence of anxiety could impact dementia risk, as chronic anxiety is associated with disorders such as neuronal apoptosis, neuronal atrophy and cardiovascular disease. “All of which are well-known risk factors for dementia,” they said.

The researchers addressed the shortcomings of previous work by utilizing longitudinal data from the Hunter Community Study (HCS). A total of 2,132 participants, aged 76 years on average, were recruited, with an average follow-up of 10 years.

Anxiety was measured using the Kessler Psychological Distress Scale at baseline (wave one) and the participant’s first follow-up five years later (wave two). The persistency of anxiety was defined as follows:

• Chronic – people who had anxiety at wave one and wave two
• Resolved – people who had anxiety only at wave one
• New onset anxiety – people who did not have anxiety at wave one, but developed it later at wave two.

The researchers also tested the effect of age of anxiety on dementia risk by subdividing participants into three groups according to their age at baseline:

• Group 1: Age 60–70
• Group 2: Age 71–80
• Group 3: Age 81+.

“While this sort of question cannot be subject to a randomized controlled trial, this prospective cohort study used causal inference methods to explore the role of anxiety in promoting the development of dementia,” said Dr. Kay Khaing, conjoint lecturer in the School of Medicine and Public Health at the University of Newcastle, and co-author of the study.

New onset anxiety is associated with a 3.2 times higher risk of developing dementia

Of the 2,132 participants, 64 (3%) developed dementia over the follow-up period.

Analyzing this data in conjunction with the Kessler Psychological Distress Scale scores, Attia and colleagues found that chronic anxiety was associated with a 2.8 times higher risk of developing dementia. In comparison, new onset anxiety was associated with a 3.2 times higher risk. These risk scores were higher for individuals younger than 70 years old.

“We found that being anxious (either chronic or new onset) below the age of 70 years increased the risk of dementia, compared to those aged 70 and above. This was somewhat in agreement with the previous studies showing that being anxious at younger ages was associated with increased risk of cardiovascular disease, and anxiety at middle age was related to all-cause and cardiovascular death,” Attia and colleagues said. “Our cohort did not include people younger than 60, so we were unable to compare our results for the younger range of middle age.”

Participants whose anxiety resolved between wave one and wave two did not show a greater risk of developing dementia – their risk was similar to individuals who did not score for anxiety symptoms at baseline.

The study identifies association, not causation. Its data is also limited to an Australian cohort, warranting further research in wider groups of people across the globe. However, Attia and colleagues are confident that anxiety could be a modifiable risk factor for dementia – treat the anxiety, and you might reduce the risk.

Reference: Khaing K, Dolja-Gore X, Nair BR, Byles J, Attia J. The effect of anxiety on all-cause dementia: A longitudinal analysis from the Hunter Community Study. JAGS. 2024. doi: 10.1111/jgs.19078