Surviving disaster may up dementia risk

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Older adults who live through a disaster may also face an increased risk of dementia and cognitive impairment, according to a recent study.

Previous research on disasters' effects on mental health has largely focused on post-traumatic stress disorder, said lead researcher Hiroyuki Hikichi, Ph.D., of Harvard's T.H. Chan School of Public Health. 

The study focused on the 2011 tsunami in Japan and older adults who had to leave their homes as a result of it. In a health survey conducted seven months before the tsunami, 4.1% of residents in one hard-hit area reportedly displayed dementia symptoms.

In a follow-up survey conducted by Hikichi two and a half years after the tsunami, the respondents who were assessed as having dementia symptoms nearly tripled to 11.5%. Those seniors whose homes were damaged or destroyed during the tsunami reported the highest levels of cognitive decline.

“It appears that relocation after a disaster may have the unintended effect of separating people not just from their homes but from their neighbors — and both may speed up cognitive decline,” Hikichi said.