Neuropsychiatric symptoms (NPS) are commonly observed in individuals with dementia with Lewy bodies (DLB).  Hallucinations, motor abnormalities, REM sleep behavior disorder, as well as attention and cognitive fluctuations, are hallmarks of DLB. Previous studies have indicated that apathy, depression, anxiety, and delusions are also associated with DLB. This study investigated the extent to which hallucinations, motor disturbances, nighttime behaviors, disinhibition, apathy, depression, anxiety, and delusions are predictive of everyday functioning in prodromal DLB.

Participants included healthy older controls, (n=54), MCI with DLB etiology (n=214), and DLB (n=1045). All participants were eventually diagnosed with DLB upon later visits in the longitudinal study. The Neuropsychiatric Inventory Questionnaire (NPI-Q) and the Functional Activities Questionnaire (FAQ) data were administered. The FAQ was used to assess everyday functioning abilities through caregiver reports.

Multiple linear regressions were performed to assess the impact of NPS on total FAQ scores, with age being a covariate. The results indicated that apathy was predictive of everyday functioning in the control and MCI groups. Anxiety was also predictive of everyday functioning in the MCI group.

Our findings indicated that some NPS, particularly apathy and anxiety, impacted everyday functioning in MCI participants who would eventually be diagnosed with DLB. These results suggest that assessing for apathy and anxiety in MCI may be useful for early identification and intervention in the earliest stages of DLB.