A 37-year follow-up study found the major risk factors associated with young-onset dementia disease (dementia diagnosed under age 65) included alcohol intoxication, stroke, use of antipsychotics, depression, below average height, father’s dementia, drug intoxication, low cognitive function at 18 years of age, and high systolic blood pressure at 18 years of age. Men who had at least two of the nine risk factors and were also in the lowest third of cognitive function at age 18 had a 20-fold increased risk for a dementia diagnosis before age 65.
JAMA Internal Medicine, August 2013