Seniors who have experienced episodes of delirium have a significant risk of developing dementia, new research suggests.           

Delirium, a mental state with acute bouts of confusion and disorientation, affects about 15% of hospitalized seniors. It has long been characterized as a temporary side effect of infection, medications or inpatient procedures. Delirium also is associated with an increased risk for nursing home admission.

Investigators from University of Cambridge and the University of Eastern Finland followed a group of 553 people aged 85 and over for 10 years. In the people without pre-existing dementia, bouts of delirium resulted in an eight-fold increase in the risk for dementia. Moreover, in participants with existing dementia, delirium worsened the severity of their symptoms and increased their risk of mortality.

The study was published Aug. 9 in the journal Brain.