Researchers on Sunday outlined a syndrome called "mild behavioral impairment" that may be a harbinger of Alzheimer's or other dementias, and proposed a checklist of symptoms to help identify who's at risk. The symptoms must mark a change from prior behavior and have lasted at least six months. Among the questions:

— Has the person lost interest in friends, family or home activities?

— Has the person become less spontaneous and active — for example, is he/she less likely to initiate or maintain conversation?

— Does the person view herself/himself as a burden to family?

— Has the person become more anxious or worried about things that are routine, like events, visits?

— Does the person feel very tense, having developed an inability to relax, or shakiness, or symptoms of panic?

— Has the person become agitated, aggressive, irritable or temperamental?

— Does the person hoard objects when she/he did not do so before?

— Has the person recently developed trouble regulating smoking, alcohol, drug intake or gambling, or started shoplifting?

— Does the person say rude or crude things or make lewd sexual remarks that she/he would not have said before?

— Has the person started talking openly about very personal or private matters not usually discussed in public?

— Has the person developed beliefs that they are in danger, or that others are planning to harm them or steal their belongings?

— Does the person report or act as if seeing things or hearing voices?