Neuroimaging of delusions in Alzheimer's disease

MEDLINE, Embase and PsycINFO were searched using the keywords "imaging", "neuroimaging", "CT", "MRI", "PET", "SPECT", "Alzheimer's", "dementia", "delusions" and "psychosis" to find studies specifically assessing or reporting on neuroimaging of delusions in Alzheimer's Dementia (AD), separate from hallucinations or psychosis in general in AD. Twenty-five studies were found meeting criteria and are included in this review which reports on structural, regional perfusion, metabolic and receptor binding imaging modalities assessing delusions as a whole, as well as persecutory and misidentification delusional subtypes. The majority of studies implicate right-sided pathology, primarily frontal lobe. Left-frontal predominance and release, secondary to right-sided pathology, may create a hyperinferential state resulting in the formation of delusions. This perturbation and imbalance of normal networks is associated with delusional phenomenology. Temporal lobe structures are also important in misidentification syndromes, which have a different natural history than paranoid delusions. Consistent with the neuropathological and genetic literature, neuroimaging has shown that paranoid versus misidentification delusions are associated with different phenomenology and different neural substrates. Delusional subtype is an important factor in understanding the neurobiological underpinnings of delusions in dementia. We also discuss methodological issues related to neuroimaging of delusions in AD.     

Psychiatric symptoms vary with the severity of dementia in probable Alzheimer's disease

This cross-sectional study examines relationships among the constellation of psychiatric syndromes in Alzheimer's disease (AD) as a function of dementia severity in 1155 patients with probable AD. The frequency of major depression decreased in severe stages, while agitation, aggression, and psychosis were more frequent in late stages. Major depression was associated with anhedonia, sleep disorders, depressed mood, low self-esteem, anxiety, and hopelessness in mild/moderate and severe stages. Agitation was associated with aggression and psychosis in mild/moderate stages, and psychosis was associated with aggression in moderate/severe stages. In addition, there was a constellation of psychiatric symptoms (e.g., anxiety, wandering, irritability, inappropriate behavior, uncooperativeness, emotional lability) associated with agitation, aggression, and psychosis, which varied according to the severity of the dementia, suggesting a progressive deterioration of frontal-temporal limbic structures. Education and race were independently associated with psychosis. However, while education was associated with psychosis in mild/moderate stages, race was associated with psychosis in moderate/severe stages.     

Anosognosia and neuropsychiatric symptoms and disorders in mild Alzheimer disease and mild cognitive impairment

Anosognosia is a multidimensional phenomenon that negatively affects course of illness. This study aimed to explore the association between anosognosia and neuropsychiatric phenomena in mild Alzheimer's disease (AD) and in mild cognitive impairment (MCI). The Anosognosia Questionnaire for Dementia to assess anosognosia, and the Neuropsychiatric Inventory to assess neuropsychiatric symptoms were administered to 209 patients (103 mild AD, 52 amnestic-MCI, and 54 amnestic multidomain-MCI). Categorical diagnoses of apathy, depression, and psychosis were made using specific criteria for dementia. With regard to continuous scores, in mild AD, we found positive correlation between symptoms of anosognosia and apathy, agitation and aberrant motor behaviors, while in MCI, we did not find significant association. At a categorical level, the diagnosis of anosognosia in mild AD was associated with the diagnosis of apathy. In mild AD, the frequent co-occurrence of frontally mediated behavioral disorders and anosognosia, particularly apathy, supports the hypothesis of a shared neuropsychogenic process due to the disruption of frontal brain networks.     

The epidemiology of psychosis in dementia.

OBJECTIVE: Authors compared delusions, hallucinations, and misidentification delusions in Alzheimer disease (AD) and vascular dementia (VaD) patients. METHODS: The authors report data on the prevalence, severity, clinical, and demographic associations of these symptoms in a population sample of 260 persons with dementia, examined with the Neuropsychiatric Inventory. RESULTS: The primary finding was that there was no difference in psychosis as a whole, or in delusions and hallucinations, between AD and VaD. Also, in AD, female gender appeared to be a risk factor for delusions; subjects in an earlier stage of dementia showed fewer delusions. CONCLUSION: The profile of delusions and hallucinations seen is different from that seen in schizophrenia, further supporting the hypothesis that AD-associated psychosis is a distinct phenomenological syndrome.     

Role of serotonin transporter polymorphisms in the behavioural and psychological symptoms in probable Alzheimer disease patients

BACKGROUND/AIMS: Alzheimer disease (AD) patients commonly suffer from behavioural and psychological symptoms of dementia (BPSD). A genetic component to BPSD development in AD has been demonstrated. This is an investigation of whether the linked polymorphic region and variable number tandem repeat variants of the serotonin transporter (SERT) are associated with BPSD. METHODS: The longitudinal measures of BPSD of our large cohort of 367 AD patients were assessed by the Neuropsychiatric Inventory. Measures with good evidence of serotonergic involvement (delusions, hallucinations, depression, anxiety, agitation/aggression and irritability) were related to genotype and allele frequencies of the linked polymorphic region and variable number tandem repeat variants. RESULTS: Analysis revealed significant relationships between the linked polymorphic region variant long allele with irritability and the variable number tandem repeat 10-repeat allele with psychosis, but no associations were found with depression, anxiety or agitation/aggression. CONCLUSION: Our data and review of previous studies suggest SERT could play a minor role in development of psychosis and aggressive/irritable tendencies; however, further investigations are required in large, well-characterized cohorts.     

Non-cognitive symptoms in mild cognitive impairment subjects

The term mild cognitive impairment (MCI) is used to identify individuals with worse cognitive performance than those with normal aging, and who are at risk of dementia, especially Alzheimer's disease (AD). Although the MCI concept is based on the presence of specific cognitive deficits, several studies have shown that these subjects can develop depression, disruptive behaviors (e.g., agitation, aggression), and psychosis. In this study, we examined the baseline psychiatric characteristics of 228 MCI (Mean age: 71.2, Mini-mental State Examination [MMSE] score: 25.9) and 427 mildly demented Probable AD (Mean age: 73.2; Mean MMSE score: 23.5) subjects from a referral dementia clinic. The psychiatric assessment was conducted by geriatric psychiatrists using semi-structured interviews. The proportion of subjects with major depression (MCI: 7.5% vs. Probable AD: 8%) and aggression (MCI: 10% vs. Probable AD: 12.5%) was similar in the two groups. There were more Probable AD patients with psychomotor agitation (52% vs. 38%), delusions (29% vs. 14%), and hallucinations (9% vs. 4%) than MCI subjects. Within MCI groups, we did not observe any differences between MCI subjects with amnesic syndrome versus MCI subjects with a much broader cognitive deficit. These results showed that the MCI syndrome is not circumscribed to a neuropsychological definition, but occurs with a wide range of psychiatric syndromes. Furthermore, it is possible that the development of disruptive behaviors and psychosis, in MCI subjects with no previous history of psychiatric illness, constitutes a strong indication that there is an underlying neurodegenerative disorder.     

Long-term follow-up and phenomenologic differences distinguish among late-onset schizophrenia, late-life depression, and progressive dementia.

OBJECTIVE: The diagnosis of patients with late-life onset of hallucinations and delusions but an absence of mood or cognitive disorder remains controversial. The authors used long-term follow-up and phenomenology to assess whether outcome varied by diagnosis. METHODS: Twenty-eight individuals with late-life psychosis but no mood or cognitive disorder were compared with 48 individuals with late-life major depression and 47 individuals with psychotic symptoms and late-life dementia. All subjects were followed for a minimum of 1 year. Data from the last time examined were used to determine likelihood of death at 84 months by Kaplan-Meier analysis in all groups and the likelihood of developing dementia in the depression and late-life onset psychosis groups at 120 months. RESULTS: Patients with dementia-plus-psychosis were more likely to die at 84 months than those with major depression or late-onset hallucinations and delusions. Subjects with depression or late-onset hallucinations and delusions did not differ in likelihood of developing dementia at 120 months. CONCLUSIONS: These results support the hypothesis that a condition characterized by psychiatric symptoms and no mood symptoms can begin in later life and that this disorder is not a precursor to dementia.     

Neuropsychiatric symptoms in the dementias

PURPOSE OF REVIEW: Neuropsychiatric, or non-cognitive symptoms are increasingly recognized as manifestations of dementias. RECENT FINDINGS: In Alzheimer's disease, recent advances have included the identification of behavioral profiles, differentiation of apathy and depression, characterization of risk factors for psychosis and its links to agitation and aggression, and an analysis of depressive symptoms in the absence of major depression. Functional neuroimaging data mainly supported the role of the anterior cingulate in apathy. The orbitofrontal and anterior cingulate tangle burden were associated with agitation, and increased orbitofrontal and mid-temporal muscarinic M2 receptors with psychosis and hallucinations. Selected genetic polymorphisms of dopamine and serotonin receptors or transporters were linked with aggression, hallucinations or psychosis. When compared with other dementias, individuals with frontotemporal dementia disclosed, as expected, different behaviors and particularly aberrant social behavior. The frequency of delusions and visual hallucinations was increased in Parkinson's disease, Parkinson's disease with dementia, and dementia with Lewy bodies, suggesting common mechanisms such as Lewy body pathology and cholinergic deficiency. The latter was supported by an improvement of these symptoms by cholinesterase inhibitors. SUMMARY: Future research directions include both clinical and basic neuroscience investigations. The detection of early neuropsychiatric symptoms might be a marker for dementia, and the possible existence of a mild neuropsychiatric impairment syndrome should be explored. More longitudinal studies with pathological confirmation will facilitate correlations with neuropsychiatric symptoms. Functional neuroimaging and behavioral neurogenetics will permit in-vivo correlations and consequently help patient management and care.     

Psychotic symptoms in Alzheimer disease: evidence for subtypes.

OBJECTIVE: Psychotic symptoms in Alzheimer disease (AD) identify a phenotype with distinct neurobiology and genetic architecture. The authors investigated whether AD with psychosis is homogeneous or is a composite of subtypes. METHODS: Authors performed factor and cluster analyses of the psychotic-symptom items of the CERAD Behavioral Rating Scale in 188 probable and possible AD subjects who have displayed at least one psychotic symptom. RESULTS: Exploratory factor analysis resulted in a one-factor solution that comprised misidentification delusions, auditory and visual hallucinations, and the misidentification of people. Persecutory delusions were also frequently present and were independent of the misidentification/hallucination factor. Cluster analysis yielded similar results. CONCLUSION: Misidentification/hallucinations and persecutory delusions may identify two subtypes of psychosis in AD. Longitudinal study is needed to determine whether these proposed subtypes remain stable and independent over time or merge into a single group over the course of illness.     

The effects of olanzapine in reducing the emergence of psychosis among nursing home patients with Alzheimer's disease

BACKGROUND: Elderly patients with Alzheimer's disease (AD) commonly exhibit psychotic symptoms, prompting clinicians to administer antipsychotics. This article compares the effects of olanzapine and placebo in the emergence of hallucinations or delusions in AD patients with symptoms of agitation/aggression but little or no psychotic symptomatology at baseline. METHOD: A multicenter, double-blind, placebo-controlled study was conducted in nursing home patients with AD according to DSM-IV criteria and symptoms of agitation/aggression and/or psychosis. Patients (N = 206) were randomly assigned to receive either placebo or fixed-dose olanzapine (5, 10, or 15 mg/day) for up to 6 weeks. This article analyzes data from a subgroup of patients (N = 165) with no or minimal delusions and/or hallucinations at baseline as measured by the Neuropsychiatric Inventory-Nursing Home Version (NPI/NH). Three subsets of patients were identified on the basis of their symptoms at baseline: those with no clinically significant hallucinations, those with no clinically significant delusions, and those with no clinically significant delusions or hallucinations. RESULTS: Of the patients without hallucinations or delusions at baseline (N = 75), the placebo-treated patients showed significantly greater development of these symptoms compared with olanzapine-treated patients overall (NPI/NH hallucinations + delusions mean change score, +2.73 vs. +0.27, p = .006). Similarly, of the patients without baseline hallucinations (N = 153), the placebo-treated patients showed greater hallucinations score increases than did olanzapine-treated patients overall (+1.25 vs. +0.33, p = .026), whereas patients without baseline delusions (N = 87) showed no significant treatment effects. Olanzapine had a favorable safety profile in each patient subset. CONCLUSION: These results suggest that, overall, olanzapine effectively attenuated emergence of psychosis in a short-term trial of patients with Alzheimer's disease.     

A double-blind comparison of citalopram and risperidone for the treatment of behavioral and psychotic symptoms associated with dementia.

OBJECTIVE: To compare citalopram and risperidone for the treatment of psychotic symptoms and agitation associated with dementia, with a priori hypotheses that risperidone would be more efficacious for psychosis and citalopram for agitation. METHODS: A 12-week randomized, controlled trial in nondepressed patients with dementia hospitalized because of behavioral symptoms (N = 103) was conducted at the University of Pittsburgh Medical Center. Participants were consecutively recruited on an inpatient unit if they had at least one moderate to severe target symptom (aggression, agitation, hostility, suspiciousness, hallucinations, or delusions). Once they improved sufficiently, they were discharged to nursing homes, personal care homes, or residential homes for continued treatment. Planned pre-post and mixed model analyses of the main outcome measures of Neurobehavioral Rating Scale and Side Effect Rating Scale at baseline and at weekly/biweekly intervals were conducted. RESULTS: Completion rates did not differ for citalopram and risperidone (overall completion rate: 44%). Agitation symptoms (aggression, agitation, or hostility) and psychotic symptoms (suspiciousness, hallucinations, or delusions) decreased in both treatment groups but the improvement did not differ significantly between the two groups. There was a significant increase in side effect burden with risperidone but not with citalopram such that the two groups differed significantly. CONCLUSION: No statistical difference was found in the efficacy of citalopram and risperidone for the treatment of either agitation or psychotic symptoms in patients with dementia. These findings need to be replicated before citalopram or other serotonergic antidepressants can be recommended as alternatives to antipsychotics for the treatment of agitation or psychotic symptoms associated with dementia.     

Psychosis in Parkinson's disease without dementia: Common and comorbid with other non‐motor symptoms

Psychosis in Parkinson's disease (PD) is common and associated with a range of negative outcomes. Dementia and psychosis are highly correlated in PD, but the frequency and correlates of psychosis in patients without cognitive impairment are not well understood. One hundred and ninety‐one non‐demented PD patients at two movement disorders centers participated in a study of neuropsychiatric complications in PD and completed a detailed neurological and neuropsychiatric assessment, including the rater‐administered Parkinson Psychosis Rating Scale for hallucinations, delusions, and minor symptoms of psychosis (illusions and misidentification of persons). Psychotic symptoms were present in 21.5% of the sample. Visual hallucinations were most common (13.6%), followed by auditory hallucinations (6.8%), illusions or misidentification of people (7.3%), and paranoid ideation (4.7%). Visual hallucinations and illusions or misidentification of people were the most common comorbid symptoms (3.1%). Depression (P = 0.01) and rapid eye movement behavior disorder symptoms (P = 0.03) were associated with psychosis in a multivariable model. The odds of experiencing psychotic symptoms were approximately five times higher in patients with comorbid disorders of depression and sleep‐wakefulness. Even in patients without global cognitive impairment, psychosis in PD is common and most highly correlated with other non‐motor symptoms. Screening for psychosis should occur at all stages of PD as part of a broad non‐motor assessment. In addition, these findings suggest a common neural substrate for disturbances of perception, mood, sleep‐wakefulness, and incipient cognitive decline in PD. © 2012 Movement Disorder Society     

The psychotic phenomenon in probable Alzheimer's disease: a positron emission tomography study

Positron emission tomography was used to examine the mechanisms of the psychotic phenomenon in Alzheimer's disease (AD). Data from 2 patients with delusions and 2 with hallucinations were compared with those of 5 AD patients without psychosis. The patients with paranoid delusions had diminished relative regional cerebral blood flow (rel-CBF) in the left dorsolateral prefrontal and left medial temporal cortices. The patients with visual hallucinations showed diminished rel-CBF in the right parietal, left medial temporal, and left dorsolateral prefrontal cortices. These findings support the hypothesis that a frontal-temporal abnormality is associated with paranoid delusions in AD. By contrast, visual hallucinations are associated with parietal as well as frontal and temporal lobe dysfunction. In these patients, a left prefrontal-temporal cortex dysfunction appears to be a common denominator for the development of the psychotic phenomenon in AD.     

Behavioral and psychological symptoms of dementia in untreated Alzheimer's disease patients

Background: To ascertain the prevalence of psychotic symptoms and behavioral disturbances of dementia patients is useful for families and health care professionals in order to anticipate the progression of Alzheimer’s disease (AD) and to recognize deterioration. This study aimed to determine whether behavioral and psychological symptoms of dementia (BPSD) are related to severity of untreated AD. Methods: Two hundred and two patients were classified into three groups by Functional Assessment Staging score as follows: mild group (n = 92) was at stages 3 or 4; moderate group (n = 80) was at stage 5; and severe group (n = 30) was at stages 6 or 7. We then compared the prevalence of BPSD among the groups. Psychiatric symptoms of BPSD were defined as including hallucinations, delusions, delusional misidentification syndrome and depressive mood; while behavioral disturbances included physical aggression, wandering, adverse sleep and hyperphagia. Results: In our study, depressive mood, physical aggression and wandering were statistically associated with the severity of AD. Conclusion: These results are meaningful for caregivers in helping them to understand the anticipated progression of AD and to recognize deterioration. In the care of AD patients, it is necessary to be aware of characteristics of each BPSD.     

Anosognosia in Alzheimer's disease: association with patient characteristics, psychiatric symptoms and cognitive deficits

Anosognosia is one of the major problems in the treatment and care of Alzheimer's disease (AD) patients. The aim of the study was to determine the patient characteristics, psychiatric symptoms, and cognitive deficits associated with anosognosia, because these are currently poorly understood. Eighty-four patients who met the National Institute of Neurological and Communicative Disease and Stroke-Alzheimer's Disease and Related Disorders Association criteria for probable AD were examined for anosognosia based on the difference between questionnaire scores of the patient and their caregiver. The relationship of anosognosia with patient characteristics (age, age at onset, duration of illness, education, Mini-Mental State Examination (MMSE), Clinical Dementia Rating (CDR), Hyogo Activities of Daily Living Scale (HADLS)), psychiatric symptoms (Neuropsychiatric Inventory (NPI), Geriatric Depression Scale (GDS)), and cognitive function (Digit Span, Word Fluency Test, Trail Making Test, Stroop Test, Raven's Coloured Progressive Matrices Test) were studied. Anosognosia showed positive correlations with age, age at onset, duration of illness, CDR, HADLS, and NPI disinhibition, and negative correlations with MMSE and GDS. Regarding cognitive function, only Part III of the Stroop Test was a predictor of anosognosia. The severity of anosognosia increased with disease progression and with a later age at onset. Subjective complaints of depression requiring self-monitoring of mood tended to decrease and, in contrast, inhibition of socially unsuitable behavior became more difficult as anosognosia worsened. Regarding cognitive function, anosognosia appeared to be associated with response inhibition impairment. Both disinhibition, as a psychiatric symptom, and response inhibition impairment are known to be correlated with disturbance of orbitofrontal function, which therefore may be associated with anosognosia.     

Psychoses in patients with Parkinson's disease; their frequency, phenomenology, and clinical correlates]

The frequency, phenomenology, and risk factors of hallucinations and delusions were investigated in 64 consecutive inpatients with Parkinson's disease. Fifty patients were admitted to our hospital with symptoms related to Parkinson's disease: psychiatric problems 27 (psychosis 22; anxiety 2; depression 2; mania 1): motor symptoms, 20 (wearing-off 5; akinesia 4; freezing 4; postural instability 4; dyskinesia 2; tremor 2; dystonia 1), and sensory symptoms, 3. Fourteen patients were admitted with other medical problems (pneumonia 4; cerebral infarction 3; bone fracture 3; lumbago 2; seizure 1; cat bite 1). Totally 49 patients had psychiatric problems. Psychosis was present in 43 patients, dementia in 10, depression in 8, mania in 1, anxiety in 10, agitation in 6, stereotypy in 2, and hypersexuality in 2. Of the 43 patients with psychoses, 40 presented with visual hallucinations, 18 with auditory hallucinations, and 23 with delusions. To determine what the clinical correlates with the severity of psychosis were, we divided the patients into 3 groups: the severe group, 22 patients admitted because of psychotic symptoms; the mild group, 21 patients admitted because of problems other than psychosis but presenting psychotic symptoms; and the control group, 21 patients who had no psychotic symptoms. Incidences of auditory hallucinations and delusions were higher in the severe group as compared to the mild group. Patients in the severe group had higher Hoehn-Yahr stages, lower Mini-Mental State Examination scores, decreased H/M ratios of cardiac 123I-MIBG uptake, and lower frequencies of background activity on electroencephalograms. There were no differences in age at admission, age at onset of Parkinson's disease, duration of illness, amounts of levodopa and dopamine agonists received, Hamilton's depression rating scores, and brain MR findings, including atrophy and ischemic changes. Emergence of psychotic symptoms in parkinsonian patients appears to be clearly associated with impaired cognitive function. Therefore, it may be associated with the disease process itself. Terms such as dopaminomimetic or levodopa-induced psychosis may not be appropriate when describing psychosis in Parkinson's disease.     

Incidence of and risk factors for hallucinations and delusions in patients with probable AD

OBJECTIVE: To examine the incidence of and risk factors for hallucinations and delusions associated with patients clinically diagnosed with probable AD. BACKGROUND: Estimates of the incidence of psychosis in AD range widely from 10% to 75%. The risk factors for psychosis of AD are not known, although multiple studies indicate that AD patients with psychosis demonstrate greater cognitive and functional impairment. METHODS: The authors conducted psychiatric evaluations of 329 patients with probable AD from the University of California at San Diego Alzheimer's Disease Research Center to determine the incidence of hallucinations and delusions. They examined data from annual clinical and neuropsychological evaluations to determine whether there were specific risk factors for the development of hallucinations and delusions. RESULTS: Using Cox survival analyses, the cumulative incidence of hallucinations and delusions was 20.1% at 1 year, 36.1% at 2, 49.5% at 3, and 51.3% at 4 years. Parkinsonian gait, bradyphrenia, exaggerated general cognitive decline, and exaggerated semantic memory decline were significant predictors. Age, education, and gender were not significant predictors. CONCLUSIONS: The authors found a relatively high incidence of hallucinations and delusions in patients diagnosed with probable AD and suggest that specific neurologic signs, cognitive abilities, and accelerated decline may be predictive markers for their occurrence.     

Patient versus informant reported quality of life in the earliest phases of Alzheimer's disease

OBJECTIVES: The study investigated if patient and informant reported Quality of Life (QoL) differed in early Alzheimer's disease (AD). In addition, we examined whether anosognosia had an impact on the agreement between patient and informant ratings of QoL and whether anosognosia, dementia severity, depression and behavioural symptoms were significantly correlated to QoL in early AD. METHODS: From a prospective research program including newly referred patients (age >60 years and MMSE > or = 20), 48 patients with very early AD were included. QoL was assessed using the QoL-AD and EQ-5D scales. Anosognosia was rated on a categorical scale by an examiner. MMSE, Geriatric Depression Scale, Danish Adult Reading Test and Frontal Behavioural Inventory were also administered. RESULTS: On most QoL measures patients rated their QoL higher than their informants. Anosognosia was not associated with QoL but significantly with an inverse impact on the agreement between patient and informant ratings of QoL. Self-reported QoL was significantly correlated to depression but not to age, dementia severity, behavioural symptoms or memory impairment. Informant ratings of QoL were significantly correlated to behavioural symptoms and informant ratings on the EQ-5D Visual Analogue Scale were significantly correlated to patient reported depression. CONCLUSION: Patients with early AD generally reported higher QoL than their informants. This disagreement was associated with the presence of anosognosia. Self-reported QoL did not correlate with the MMSE score. Behavioural changes and depressive symptoms may be associated with low QoL.     

The interrelations between psychosis, behavioral disturbance, and depression in Alzheimer disease

Behavioral changes are common in Alzheimer disease (AD), and heterogeneous in their presentation. Subtle personality changes tend to occur early; these include apathy, irritability and inability to pay attention. Later agitation, aggression and disinhibited behaviors may appear. We have utilized the Columbia University Scale for Psychopathology in Alzheimer's Disease to monitor a number of behavioral symptoms in 235 patients with early probable AD. Markov analyses were used to predict the probability of developing or retaining a given symptom at 6-month follow-up. The results show that the symptoms of psychopathology in AD fluctuate with time. Agitation was both the most frequent and persistent symptom, while paranoid delusions and hallucinations were less persistent. Most behavioral disturbances, except paranoid delusions, were associated with greater cognitive impairment. There was no association between depressive features and either cognitive or functional impairment. These results have important implications for the optimal treatment of the psychopathological symptoms of AD.