Persistent Anxiety Tied to Future Dementia

Persistent anxiety raised the risk of all-cause dementia in older adults, a longitudinal study showed.

Both chronic anxiety (HR 2.80, 95% CI 1.35-5.72, P=0.01) and new-onset anxiety (HR 3.20, 95% CI 1.40-7.45, P=0.01) were tied to an increased risk of dementia at follow-up, according to Kay Khaing, MMed, of the University of Newcastle in New Lambton, Australia, and co-authors.

Resolved anxiety cases, however, had similar risk of dementia as people without anxiety, Khaing and colleagues reported in the Journal of the American Geriatrics Society.

The results were driven primarily by chronic anxiety (HR 4.58, 95% CI 1.12-18.81, P=0.03) and new-onset anxiety (HR 7.21, 95% CI 1.86-28.02, P=0.004) in people who were younger than age 70. Anxiety did not have a significant relationship with dementia risk in the other age groups.

“These findings point out the importance of the role of anxiety and its management and also point out the high-risk age group, enabling us to focus on managing anxiety for those at risk,” Khaing wrote in an email to MedPage Today.

“Awareness of anxiety is of importance,” she added. “Seeking help if anxious, excessively or persistently, is crucial.”

Anxiety disorders have been associated with dementia, but findings have been inconsistent. Most studies assessing the relationship between anxiety and cognition have been cross-sectional or retrospective analyses.

This may be the first study examining the possible effects of persistent anxiety in older adults over time, Khaing and co-authors noted.

“Our study tested the risk of dementia in different anxiety groups — chronic anxiety, new-onset anxiety, and resolved anxiety — whereas most previous studies assessed the risk of dementia and anxiety only at baseline,” Khaing said.

For their analysis, Khaing and colleagues studied 2,132 people ages 55 to 85 in the longitudinal Hunter Community Study in Australia, excluding participants with self-reported dementia, Alzheimer’s dementia, or cognitive impairment at baseline.

Anxiety symptoms were assessed in two waves of the study, which were 5 years apart, using the Kessler Psychological Distress Scale (K10). Chronic anxiety was defined as anxiety based on K10 scores at both wave 1 and wave 2. Resolved anxiety was anxiety that emerged in K10 scores only at the wave 1 assessment, and new anxiety was anxiety that was present only at wave 2.

The primary outcome was incident all-cause dementia during follow-up, which was a maximum of 13 years from baseline. All-cause dementia was identified through medical records, national death data, and pharmacy codes.

About half of participants were women (53%). Mean age was 76, and 21% of participants had anxiety at baseline (wave 1).

During follow-up, 3% of the cohort developed dementia, and 7% died. The average onset of dementia was 10 years.

Anxiety is linked to vascular disease and dementia pathology through pathways like neuronal inflammation, cellular apoptosis, brain and hippocampal atrophy, beta amyloid formation and deposition, and cardiovascular disease, Khaing and co-authors noted.

“People with anxiety are more likely to engage in unhealthy lifestyle behaviors including unhealthy diet, physical inactivity, and smoking, which in turn can lead to cardiovascular disease, which is strongly associated with dementia,” they wrote. “Therefore, these are plausible direct and indirect mechanisms by which anxiety can increase the risk of dementia.”

The study has some limitations, they acknowledged. The K10 scores they used to define anxiety may possibly reflect the co-occurrence of anxiety and depression in some participants. The researchers did not know how anxiety was resolved at wave 2. In addition, some dementia cases might have been missed.

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