Several of the presenters in this session focused on behavioral and psychological symptoms of dementia (BPSD) as related to different types of dementia, including frontal lobe dementia, Lewy body dementia, and vascular dementia. A considerable amount of this discussion focused on mixed dementias (patients who might have more than one type of dementia) and the possibility of new syndromes of dementia being identified through autopsy studies and other neuropathologic studies. Dr. Hendrie described an autopsy study that reported that vascular dementia is rare, and that most cases of vascular dementia are in fact Alzheimer's disease (AD) with vascular changes. On autopsy, these patients have the plaques and tangles characteristic of AD, but also have vascular changes. Other researchers have reported that changes related to Lewy body dementia are common in patients with AD. Dr. Hendrie suggested that researchers could learn a great deal if pathologists reported the relative number of plaques and tangles, evidence of Lewy body dementia, or evidence of vascular dementia in each brain, rather than trying to categorize their findings as a single diagnosis.