Neuropsychiatric symptoms and global functional impairment along the Alzheimer's continuum.

BACKGROUND/AIMS Neuropsychiatric symptoms in Alzheimer's disease (AD) are highly prevalent. We sought to determine whether neuropsychiatric symptoms were related to global functional impairment at baseline and over a 3-year period in older normal control (NC), mild cognitive impairment (MCI) and mild AD dementia subjects. METHODS Eight hundred and twelve subjects (229 NC, 395 MCI, 188 AD) from the Alzheimer's Disease Neuroimaging Initiative study underwent cognitive and behavioral assessments over 3 years. RESULTS Greater hallucinations, anxiety and apathy were associated with greater global functional impairment at baseline, while the presence of hallucinations and apathy at baseline was associated with greater global functional impairment over time across all subjects. The following neuropsychiatric symptoms were not significantly associated with global functioning: delusions, agitation, depression, euphoria, disinhibition, irritability, aberrant motor behaviors, sleep and appetite. CONCLUSIONS These results suggest that increased baseline hallucinations, apathy and anxiety are associated with current and future disease progression in AD.