Neuropsychiatric Symptoms as Risk Factors for Progression From CIND to Dementia: The Cache County Study

Objectives: To examine the association of neuropsychiatric symptom (NPS) severity with risk of transition to all-cause dementia, Alzheimer disease (AD), and vascular dementia (VaD). Design: Survival analysis of time to dementia, AD, or VaD onset. Setting: Population-based study. Participants: 230 participants diagnosed with cognitive impairment, no dementia (CIND) from the Cache County Study of Memory Health and Aging were followed for a mean of 3.3 years. Measurements: The Neuropsychiatric Inventory (NPI) was used to quantify the presence, frequency, and severity of NPS. Chi-squared statistics, t-tests, and Cox proportional hazard ratios were used to assess associations. Results: The conversion rate from CIND to all-cause dementia was 12% per year, with risk factors including an APOE epsilon 4 allele, lower Mini-Mental State Examination, lower 3MS, and higher CDR sum-of-boxes. The presence of at least one NPS was a risk factor for all-cause dementia, as was the presence of NPS with mild severity. Nighttime behaviors were a risk factor for all-cause dementia and of AD, whereas hallucinations were a risk factor for VaD. Conclusions: These data confirm that NPS are risk factors for conversion from CIND to dementia. Of special interest is that even NPS of mild severity are a risk for all-cause dementia or AD.