Positive baseline behavioral and psychological symptoms of dementia predict a subsequent cognitive impairment in cognitively normal population

Background: Because behavioral and psychological symptoms of dementia (BPSD) are sometimes prodromal symptoms of dementia, it is important to investigate the relationship between BPSD and subsequent cognitive decline. Methods: We examined the cognitive and affective functions of 76 cognitively normal subjects at initial assessment (baseline) and 1-year follow-up. Cognitive function was assessed using clinical dementia rating (CDR) and Mini-Mental State Examination (MMSE), and affective function was assessed using Abe's BPSD score (ABS) and mild behavioral impairment (MBI). Results: Although there was no change in MMSE, ABS, or MBI after 1 year, the mean CDR score of 0 at baseline increased to 0.1 ± 0.2 at 1-year follow-up (**P < 0.01 vs baseline). No significant change in MMSE was found in both baseline ABS and MBI positive- or negative-groups. In contrast, baseline MBI-dependent CDR change showed a 13.2% of worsening in MBI-negative subjects and a 62.5% of MBI-positive subjects (††P < 0.01), but ABS not. Conclusion: The present data indicate that positive baseline BPSD with MBI was closely related to a subsequent CDR exacerbation. Examining BPSD may be useful for screening cognitively normal population for subsequent dementia development in local communities.