One in 10 Americans over 65 had dementia, while 22% experienced mild cognitive impairment, the earliest stage of the slow slide into senility, according to a new study conducted between 2016 and 2017.
The research, which the authors said is the first nationally representative examination of cognitive impairment prevalence in more than 20 years, was able to measure prevalence of dementia and mild cognitive impairment by age, education, ethnicity, gender and race.
Fifteen percent of people who identified as Black tested positive for dementia, while 22% had mild cognitive decline, the study found. Ten percent of people who identified as Hispanic had dementia, but the rate of milder issues was higher — 28% tested positive for mild cognitive impairment. Nine percent of White people had dementia, while 21% had mild cognitive impairment.
Educational achievement, which experts consider to be protective against cognitive decline, showed a significant divide: Nine percent of people with a college degree tested positive for dementia, compared with 13% of those who never received a high school diploma. Twenty-one percent of people over 65 with college degrees had mild cognitive decline, compared with 30% of those with less than a high school degree.
The extreme elderly had the highest rates of dementia and mild cognitive impairment. Only 3% of adults between 65 and 69 tested positive for dementia, compared with 35% of those 90 and older.
