Prevalence, risk factors, and impact of anxiety in early Alzheimer disease: a retrospective study of an autopsy-confirmed cohort.

Anxiety is a neuropsychiatric symptom (NPS) of Alzheimer disease (AD) patients which has been studied primarily in prospective and retrospective studies of clinically diagnosed AD. However, this can be confounded by other primary etiologies. Moreover, anxiety has not been comprehensively studied in autopsy-confirmed AD cases across subjective cognitive decline (SCD), mild cognitive impairment (MCI), and dementia stages. We conducted a retrospective longitudinal analysis of 212 participants with autopsy-confirmed AD, followed from 1986-2013 at the NYU Alzheimer's Disease Research Center with staging via the Global Deterioration Scale and NPS assessed via BEHAVE-AD. We found that anxiety varied uniquely with stage and was the most common NPS in SCD and MCI (35-40% prevalence). ApoE4 carriage associated with a higher rate of anxiety only at mild dementia. Anxiety in SCD associated with cerebral amyloid angiopathy and arteriosclerosis on brain autopsy, but there were no such associations with concomitant neuropathology at MCI and mild dementia. Anxiety associated with increased progression rate (∼2.5-fold) from SCD to MCI/dementia stages, but not from MCI to dementia. These results suggest an important relationship between anxiety and AD, especially at the preclinical stage. This warrants further study of anxiety as a possible modifiable factor of disease experience and course.