Delusions Increase Functional Impairment in Alzheimer’s Disease

Abstract

Background/Aims: Delusions in Alzheimer’s disease (AD) may be associated with functional impairment. No studies to date have used functional instruments sensitive to changes in frontal executive function, possibly underestimating the impact. Methods: Patients with AD with and without delusions were administered cognitive tests and questionnaires to assess depression and quality of life. Caregivers were administered questionnaires to assess functional impairment, caregiver burden and behavioural symptoms. Results: AD patients with delusions (n = 19) when compared to AD patients without delusions (n = 19) matched for age, education and global cognitive function were significantly more functionally impaired based on performance on the Disability Assessment for Dementia Scale (p < 0.005). Conclusion: AD patients with delusions have significantly worse functional performance.

Lewy Bodies, Vascular Risk Factors, and Subcortical Arteriosclerotic Leukoencephalopathy, but not Alzheimer Pathology, are Associated with Development of Psychosis in Alzheimer’s Disease

“…AD patients with hallucinations, both with and without delusions, had more advanced disease (higher CDR scores) and were more cognitively and functionally impaired (lower MMSE scores and higher FAQs) at the last study visit prior to death, although in the latter there was no association observed between hallucinations and cognition in the npAD group. Contrary to previous studies [4], AD+D subjects were not more functionally impaired and, in fact, had significantly less clinical disease severity at the visit prior to death when compared to AD–P subjects as measured by the MMSE and global CDR. One potential explanation for this finding is that patients with delusions had a longer interval between the last clinical assessments to time of death, so it is possible that the disease progression was less advanced at the last assessment.…”

“…While delusions are more common than hallucinations, they are often associated with greater insight and therefore are less problematic [3]. Psychotic symptoms in AD are clinically significant, as they have been shown to be associated with increased caregiver burden [4], increased functional decline [4], and more rapid disease progression [5]. The pathobiological mechanisms that underlie psychotic symptoms are unclear, limiting our ability to manage and treat these symptoms.…”

Neuropsychiatric symptoms as early manifestations of emergent dementia: Provisional diagnostic criteria for mild behavioral impairment

“…NPS are the noncognitive or behavioral and psychiatric symptoms of dementia and include disturbances of mood, perception, and behavior associated with neurodegenerative disease [1]. NPS in dementia are associated with poorer outcomes including greater caregiver burden [2], greater functional impairment [3], higher rates of institutionalization [4], poorer quality of life [5], accelerated progression to severe dementia or death [6], and higher burden of neuropathologic markers of dementia [7]. Furthermore, NPS are present in the prodromal or mild cognitive impairment (MCI) stages of dementia, with one study reporting them in 59% of subjects enrolled in a large MCI clinical trial; furthermore, these individuals with NPS had greater impairment on global, cognitive, and functional scores than those without NPS [8].…”

The Mild Behavioral Impairment Checklist (MBI-C): A Rating Scale for Neuropsychiatric Symptoms in Pre-Dementia Populations

“…NPS are common in dementia with prevalence rates of up to 97%, increasing with time after diagnosis [3]. NPS are associated with faster cognitive decline and accelerated progression to severe dementia or death [4, 5], higher rates of institutionalization [6, 7], greater functional impairment [8], greater caregiver stress [9], worse quality of life [10], and higher burden of neuropathological markers of dementia [11]. NPS are often present at the time of dementia diagnosis [3], and for some they precede the onset of cognitive symptoms [12].…”