Agitation, confusion and poor focus can all be strong risk factors for dementia and death in older age, a large new study has found.
Over 5 million Americans over the age of 65 live with dementia, according to 2014 data from the U.S. Centers for Disease Control and Prevention. Dementia comes in different forms—the most common of which is Alzheimer's disease—and is characterized by an impaired ability to remember, think and make decisions.
Exactly what causes dementia is not entirely clear, but a range of genetic and environmental risk factors have been associated with the condition.
Previous studies have found an association between sudden changes in a person's usual mental state with subsequent dementia, but the extent of this relationship has so far been unclear.
To address these uncertainties, researchers in Australia analyzed data from 626,467 patients over the age of 65 with no dementia diagnosis who had been admitted to hospital in New South Wales between January 2009 and December 2014. Their results were published in the British Medical Journal on March 27.
Of these patients, 55,211 had at least one recorded episode of delirium, symptoms of which include agitation, confusion or being unable to maintain focus.
The 55,211 patients were matched up with another 55,211 patients with comparable ages, gender, frailty, reasons for being in hospital, and duration of hospital stay. These 110,422 patients were then followed up five years later to see how many had been diagnosed with dementia during this period.
The researchers found that patients who had experienced delirium had a 39 percent higher risk of death and three times the risk of being diagnosed with dementia during the study period compared to those without delirium. This relationship was stronger in men than women, and each additional episode of delirium was associated with a 20 percent increased risk of developing dementia.
"Delirium is a factor that could triple a person's risk of dementia. Therefore, delirium prevention and treatment are opportunities to reduce dementia burden globally," the researchers write.
Of course, these findings are purely observational and more work needs to be done to confirm any biochemical mechanisms underpinning this data. Even so, these results demonstrate a clear link between delirium and dementia and warrant further study.
"While our results are consistent with the hypothesis that delirium plays a causative part in dementia, they are not conclusive owing to the fundamental limitations of observational studies in determining causality," the researchers write. "Nevertheless, the results of this study provide valuable insights."
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Uncommon Knowledge
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Newsweek is committed to challenging conventional wisdom and finding connections in the search for common ground.
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Pandora Dewan is a Senior Science Reporter at Newsweek based in London, UK. Her focus is reporting on science, health ... Read more
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