A comparison of neuropsychiatric markers in healthy subjects who progress to MCI and dementia

Behavioral and psychological abnormalities such as agitation, anxiety, and depression are common manifestations of mild cognitive impairment (MCI) and dementia. It is estimated that approximately 90% of dementia patients are affected by such neuropsychiatric symptoms over the course of their illness. This study aims to identify whether behavioral symptoms can be employed as early markers of MCI and dementia and to understand how their occurrence differs in both conditions.
The NACC database, one of the largest, most comprehensive longitudinal databases for dementia research, was used in this study. Clinician judged neuropsychiatric symptoms analyzed in this study, using multivariate logistic regression were apathy, depressed mood, visual hallucinations, auditory hallucinations, delusional beliefs, disinhibition, irritability, agitation, personality change, rapid eye movement (REM) sleep behavior disorder, and anxiety. Analysis was conducted at baseline comparing healthy individuals who progressed to MCI later in life (n = 151) vs. healthy individuals who progressed to dementia later in life (n = 137).
The average ages of healthy individuals who later progressed to MCI and of those who progressed to dementia were 77.45 and 80 years, respectively. Additionally, the mean duration of progression was 7.2 and 7.14 years for MCI and dementia, respectively.
Healthy individuals who progressed to dementia later in life were more likely to suffer from apathy (odds ratio, OR: 2.41, p: 0.002), delusional beliefs (OR: 5.66, p: 0.01), disinhibition (OR: 3.39, p: 0.02) and agitation (OR: 3.62, p: 0.003) at baseline. However, at baseline, irritability (OR: 0.49, p: 0.02) was more common in healthy individuals who later progressed to MCI (vs. those who progressed to dementia).
Neuropsychiatric abnormalities are apparent in individuals years before an official diagnosis of MCI/dementia is given. Further analysis of these factors in combination with cognitive and other dementia related-domains may enhance dementia screening and aid in a timely diagnosis.