ABSTRACT
BACKGROUND: Neuropsychiatric symptoms (NPS), such as depression, apathy, agitation, and psychotic symptoms are common in mild cognitive impairment (MCI) and dementia in Alzheimer's disease (AD). Subgroups of NPS have been reported. Yet the relationship of NPS and their subgroups to different stages of cognitive impairment is unclear. Most previous studies are based on small sample sizes and show conflicting results. We sought to examine the frequency of NPS and their subgroups in MCI and different stages of dementia in AD. METHODS: This was a cross-sectional study using data from a Norwegian national registry of memory clinics. From a total sample of 4,571 patients, we included those with MCI or AD (MCI 817, mild AD 883, moderate-severe AD 441). To compare variables across groups ANOVA or χ 2-test was applied. We used factor analysis of Neuropsychiatric Inventory Questionnaire (NPI-Q) items to identify subgroups of NPS. RESULTS: The frequency of any NPS was 87.2% (AD 91.2%, MCI 79.5%; p < 0.001) and increased with increasing severity of cognitive decline. The most frequent NPS in MCI was depression. Apathy was the most frequent NPS in AD across different stages of severity. The factor analysis identified three subgroups in MCI and mild AD, and a fourth one in moderate-severe AD. We labelled the subgroups "depression," "agitation," "psychosis," and "elation." CONCLUSIONS: The frequency of NPS is high in MCI and AD and increases with the severity of cognitive decline. The subgroups of NPS were relatively consistent from MCI to moderate-severe AD. The subgroup elation appeared only in moderate-severe AD.
Subject(s)
Alzheimer Disease/diagnosis , Cognitive Dysfunction/diagnosis , Neuropsychological Tests/statistics & numerical data , Aged , Aged, 80 and over , Alzheimer Disease/epidemiology , Alzheimer Disease/psychology , Cognitive Dysfunction/epidemiology , Cognitive Dysfunction/psychology , Cross-Sectional Studies , Factor Analysis, Statistical , Female , Humans , Male , Middle Aged , Norway/epidemiology , Psychiatric Status Rating Scales , Severity of Illness IndexABSTRACT
OBJECTIVE: To test the hypothesis that depressive symptoms correlate with Alzheimer's disease (AD) type changes in CSF and structural and functional imaging including hippocampus volume, cortical thickness, white matter lesions, Diffusion tensor imaging (DTI), and fluoro-deoxy-glucose positron emission tomography (FDG-PET) in patient with subjective (SCI) and mild (MCI) cognitive impairment. METHOD: In 60 patients, depressive symptoms were assessed using the Geriatric Depression Scale. The subjects underwent MRI, 18F-FDG PET imaging, and lumbar CSF extraction. RESULTS: Subjects with depressive symptoms (n=24) did not have more pathological AD biomarkers than non-depressed. Uncorrected there were trends towards larger hippocampal volumes (P=0.06), less orbital WM damage measured by DTI (P=0.10), and higher orbital glucose metabolism (P=0.02) in the depressed group. The findings were similar when SCI and MCI were analyzed separately. Similarly, in patients with pathological CSF biomarkers (i.e., predementia AD, n=24), we found that correlations between scores on GDS and CSF Aß42 and P-tau indicated less severe AD-specific CSF changes with increasing depression. CONCLUSION: Depressive symptoms are common in SCI/MCI, but are not associated with pathological imaging or CSF biomarkers of AD. Depression can explain cognitive impairment in SCI/MCI or add to cognitive impairment leading to an earlier clinical investigation in predementia AD.
