When the study began, none had dementia but more than 53,000 had PTSD.
During the follow-up period, more than 31,000 veterans, or 17.2 percent, were diagnosed with dementia. Veterans with PTSD had a dementia rate of almost 11 percent. Those who did not have PTSD had a rate of 6.6 percent, or almost half.
The findings appear in the June issue of /*Archives of General Psychiatry*/.