Regional brain atrophy in patients with mild Alzheimer's disease and delusions

Neuroimaging Findings of Psychosis in Alzheimer's Disease: A Systematic Review

BACKGROUND

Previous studies on neuroimaging findings in Alzheimer's disease (AD) patients with hallucinations and delusions have yielded inconsistent results. We aimed to systematically review neuroimaging findings of delusions and hallucinations in AD patients to describe the most prominent neuroimaging features.

METHODS

We performed a comprehensive search in three online databases, including PubMed, Scopus, and Web of Science in June 2023. We included studies that reported neuroimaging features of AD patients with delusion, hallucination, or psychosis.

RESULTS

After the screening, 34 studies with 2241 AD patients were eligible to be included in our qualitative synthesis. On the basis of the included studies, there are significant changes in the volume and perfusion levels of broad brain areas, including the hippocampus, amygdala, insula, cingulate, occipital, frontal, prefrontal, orbitofrontal, temporal, and parietal cortices in these patients. Moreover, AD patients with psychosis, hallucinations, or delusions reflected different EEG waves compared to AD patients without these disorders.

CONCLUSION

The results of our review provided evidence about the neuroimaging alterations in AD patients suffering from psychosis, hallucinations, and delusions using different imaging methods. AD patients with psychosis, hallucinations, or delusions have significant differences in the volume and perfusion levels of various brain regions along with alterations in EEG waves and biological molecules compared to patients with only AD.

The neural basis of neuropsychiatric symptoms in Alzheimer's disease

Neuropsychiatric symptoms (NPS) such as depression, anxiety, apathy and aggression affect up to 90% of Alzheimer's disease (AD) patients. These symptoms significantly increase caregiver stress and institutionalization rates, and more importantly they are correlated with faster cognitive decline. However, the neuronal basis of NPS in AD remains largely unknown. Here, we review current understanding of NPS and related pathology in studies of AD patients and AD mouse models. Clinical studies indicate that NPS prevalence and severity vary across different AD stages and types. Neuroimaging and postmortem studies have suggested that pathological changes in the anterior cingulate cortex, hippocampus, prefrontal cortex, and amygdala are linked to NPS, although the precise mechanisms remain unclear. Studies of AD mouse models have indicated that amyloid-beta and tau-related neurodegeneration in the hippocampus, prefrontal cortex, and anterior cingulate cortex are correlated with NPS-like behavioral deficits. A better understanding of the NPS phenotypes and related pathological changes will pave the way for developing a better management strategy for NPS in AD patients.

Adult-Onset Neuropsychiatric Symptoms as the Presenting Feature of Xeroderma Pigmentosum Group G: A Report of a Rare Case

Xeroderma pigmentosum is a rare autosomal recessive disorder resulting in heightened cutaneous photosensitivity due to aberrant DNA repair mechanisms. Early-life developmental delay and cognitive impairment have been described in xeroderma pigmentosum cases. However, psychiatric symptoms in adulthood as the presenting feature of xeroderma pigmentosum have not been reported. We report a young adult with xeroderma pigmentosum group G presenting with prominent neuropsychiatric manifestations and evidence of neurodegeneration. The clinical, laboratory, and radiological findings, skin biopsy, and the results of the genetic testing of the patient have been described after obtaining written and informed consent. A young adult male with skin photosensitivity since infancy developed hyper-religiosity, delusions, suicidal ideations, speech hypernasality, lower limb spasticity, and cognitive impairment over the past four years. The MRI of the brain showed diffuse cerebral atrophy. The skin biopsy from bilateral cheeks showed evidence of flattening and thinning of rete ridges, pigment incontinence, and perivascular and periappendageal inflammatory infiltrate. The whole exome sequencing in ethylenediaminetetraacetic acid (EDTA) blood revealed a compound heterozygous likely pathogenic mutation in intron 13 (c.2880-2A>G (3' splice site)) and a mutation in exon 15 (c.3146del (p.Asp1049ValfsTer12)) in the ERCC5 gene suggestive of xeroderma pigmentosum group G. This case highlights that prominent neuropsychiatric features in adulthood can occur due to xeroderma pigmentosum. Thus, xeroderma pigmentosum group G should be considered as a possibility among young adults presenting with neuropsychiatric features, evidence of neurodegeneration, and early-life skin photosensitivity.

Neuropsychiatric Symptoms of Alzheimer's Disease: An Anatomic-Genetic Framework for Treatment Development

BACKGROUND

Despite the burden on patients and caregivers, there are no approved therapies for the neuropsychiatric symptoms of Alzheimer's disease (NPS-AD). This is likely due to an incomplete understanding of the underlying mechanisms.

OBJECTIVE

To review the neurobiological mechanisms of NPS-AD, including depression, psychosis, and agitation.

METHODS

Understanding that genetic encoding gives rise to the function of neural circuits specific to behavior, we review the genetics and neuroimaging literature to better understand the biological underpinnings of depression, psychosis, and agitation.

RESULTS

We found that mechanisms involving monoaminergic biosynthesis and function are likely key elements of NPS-AD and while current treatment approaches are in line with this, the lack of effectiveness may be due to contributions from additional mechanisms including neurodegenerative, vascular, inflammatory, and immunologic pathways.

CONCLUSION

Within an anatomic-genetic framework, development of novel effective biological targets may engage targets within these pathways but will require a better understanding of the heterogeneity in NPS-AD.

Temporal Cortex Microarray Analysis Revealed Impaired Ribosomal Biogenesis and Hyperactivity of the Glutamatergic System: An Early Signature of Asymptomatic Alzheimer's Disease

Pathogenic aging is regarded as asymptomatic AD when there is no cognitive deficit except for neuropathology consistent with Alzheimer's disease. These individuals are highly susceptible to developing AD. Braak and Braak's theory specific to tau pathology illustrates that the brain's temporal cortex region is an initiation site for early AD progression. So, the hub gene analysis of this region may reveal early altered biological cascades that may be helpful to alleviate AD in an early stage. Meanwhile, cognitive processing also drags its attention because cognitive impairment is the ultimate result of AD. Therefore, this study aimed to explore changes in gene expression of aged control, asymptomatic AD (AsymAD), and symptomatic AD (symAD) in the temporal cortex region. We used microarray data sets to identify differentially expressed genes (DEGs) with the help of the R programming interface. Further, we constructed the protein-protein interaction (PPI) network by performing the STRING plugin in Cytoscape and determined the hub genes via the CytoHubba plugin. Furthermore, we conducted Gene Ontology (GO) enrichment analysis via Bioconductor's cluster profile package. Resultant, the AsymAD transcriptome revealed the early-stage changes of glutamatergic hyperexcitability. Whereas the connectivity of major hub genes in this network indicates a shift from initially reduced rRNA biosynthesis in the AsymAD group to impaired protein synthesis in the symAD group. Both share the phenomenon of breaking tight junctions and others. In conclusion, this study offers new understandings of the early biological vicissitudes that occur in the brain before the manifestation of symAD and gives new promising therapeutic targets for early AD intervention.

Psychosis as a Treatment Target in Dementia: A Roadmap for Designing Interventions

Psychotic phenomena are among the most severe and disruptive symptoms of dementias and appear in 30% to 50% of patients. They are associated with a worse evolution and great suffering to patients and caregivers. Their current treatments obtain limited results and are not free of adverse effects, which are sometimes serious. It is therefore crucial to develop new treatments that can improve this situation. We review available data that could enlighten the future design of clinical trials with psychosis in dementia as main target. Along with an explanation of its prevalence in the common diseases that cause dementia, we present proposals aimed at improving the definition of symptoms and what should be included and excluded in clinical trials. A review of the available information regarding the neurobiological basis of symptoms, in terms of pathology, neuroimaging, and genomics, is provided as a guide towards new therapeutic targets. The correct evaluation of symptoms is transcendental in any therapeutic trial and these aspects are extensively addressed. Finally, a critical overview of existing pharmacological and non-pharmacological treatments is made, revealing the unmet needs, in terms of efficacy and safety. Our work emphasizes the need for better definition and measurement of psychotic symptoms in dementias in order to highlight their differences with symptoms that appear in non-dementing diseases such as schizophrenia. Advances in neurobiology should illuminate the development of new, more effective and safer molecules for which this review can serve as a roadmap in the design of future clinical trials.

Paranoid and misidentification subtypes of psychosis in dementia

This study aimed to review the neurobiological and neuropsychological correlates of paranoid (persecutory delusions) and misidentification (misidentification delusions and/or hallucinations) subtypes of psychosis in dementia, to establish if they represent distinct subphenotypes. Nine studies were eligible, all included patients with Alzheimer's disease. Greater global cognitive deficits and an accelerated global cognitive decline were observed in the misidentification subtype. Neuroimaging studies showed more marked volume loss in multiple regions in patients with the misidentification subtype, including those involved in object recognition and the processing of information on spatial and temporal context. A single study found greater impairment in visual sustained attention and object recognition in the misidentification subtype. The small number of studies and methodological heterogeneity limit interpretation of the findings. Nevertheless, these findings would tentatively suggest that there may be additional or accelerated pathological change in functional networks involved in visuoperceptual processing in the misidentification subtype. This should be further explored in prospective studies and the investigation extended to other forms of dementia, to gain a transdiagnostic perspective.

Reduced Thickness of the Anterior Cingulate Cortex as a Predictor of Amnestic-Mild Cognitive Impairment Conversion to Alzheimer's Disease with Psychosis

BACKGROUND

A long-term follow-up study in patients with amnestic mild cognitive impairment (aMCI) is needed to elucidate the association between regional brain volume and psychopathological mechanisms of Alzheimer's disease with psychosis (AD + P).

OBJECTIVE

The purpose of this study was to investigate the effect of the thickness of the angular cingulate cortex (ACC) on the risk of AD + P conversion in patients with aMCI.

METHODS

This was a hospital-based prospective longitudinal study including 174 patients with aMCI. The main outcome measure was time-to-progression from aMCI to AD + P. Subregions of the ACC (rostral ACC, rACC; caudal ACC, cACC) and hippocampus (HC) were measured as regions of interest with magnetic resonance imaging and the Freesurfer analysis at baseline. Survival analysis with time to incident AD + P as an event variable was calculated with Cox proportional hazards models using the subregions of the ACC and HC as a continuous variable.

RESULTS

Cox proportional hazard analyses showed that the risk of AD + P was associated with sub-regional ACC thickness but not HC volume: reduced cortical thickness of the left cACC (HR [95%CI], 0.224 [0.087-0.575], p = 0.002), right cACC (HR [95%CI], 0.318 [0.132-0.768], p = 0.011). This association of the cACC with the risk of AD also remained significant when adjusted for HC volume.

CONCLUSION

We found that reduced cortical thickness of the cACC is a predictor of aMCI conversion to AD + P, independent of HC, suggesting that the ACC plays a vital role in the underlying pathogenesis of AD + P.

Brain mechanisms underlying neuropsychiatric symptoms in Alzheimer's disease: a systematic review of symptom-general and -specific lesion patterns

Neuropsychiatric symptoms (NPSs) are common in patients with Alzheimer's disease (AD) and are associated with accelerated cognitive impairment and earlier deaths. This review aims to explore the neural pathogenesis of NPSs in AD and its association with the progression of AD. We first provide a literature overview on the onset times of NPSs. Different NPSs occur in different disease stages of AD, but most symptoms appear in the preclinical AD or mild cognitive impairment stage and develop progressively. Next, we describe symptom-general and -specific patterns of brain lesions. Generally, the anterior cingulate cortex is a commonly damaged region across all symptoms, and the prefrontal cortex, especially the orbitofrontal cortex, is also a critical region associated with most NPSs. In contrast, the anterior cingulate-subcortical circuit is specifically related to apathy in AD, the frontal-limbic circuit is related to depression, and the amygdala circuit is related to anxiety. Finally, we elucidate the associations between the NPSs and AD by combining the onset time with the neural basis of NPSs.

Neuropsychiatric Disturbances in Alzheimer's Disease: What Have We Learned from Neuropathological Studies?

Neuropsychiatric symptoms (NPS) are an integral part of the dementia syndrome and were therefore recently included in the core diagnostic criteria of dementia. The near universal prevalence of NPS in Alzheimer's disease (AD), combined with their disabling effects on patients and caregivers, is contrasted by the fact that few effective and safe treatments exist, which is in part to be attributed to our incomplete understanding of the neurobiology of NPS. In this review, we describe the pathological alterations typical for AD, including spreading and evolution of burden, effect on the molecular and cellular integrity, functional consequences and atrophy of NPS-relevant brain regions and circuits in correlation with specific NPS assessments. It is thereby clearly established that NPS are fundamental expressions of the underlying neurodegenerative brain disease and not simply reflect the patients' secondary response to their illness. Neuropathological studies, moreover, include a majority of end-stage patient samples, which may not correctly represent the pathophysiological environment responsible for particular NPS that may already be present in an early stage, or even prior to AD diagnosis. The burdensome nature and high prevalence of NPS, in combination with the absence of effective and safe pharmacotherapies, provide a strong incentive to continue neuropathological and neurochemical, as well as imaging and other relevant approaches to further improve our apprehension of the neurobiology of NPS.

Autopsy-confirmed hippocampal-sparing Alzheimer's disease with delusional jealousy as initial manifestation

Alzheimer's disease (AD) is clinically characterized by gradual onset over years with worsening of cognition. The initial and most prominent cognitive deficit is commonly memory dysfunction. However, a subset of AD cases has less hippocampal atrophy than would be expected relative to the predominance of cortical atrophy. These hippocampal-sparing cases have distinctive clinical features, including the presence of focal cortical clinical syndromes. Given that previous studies have indicated that severe hippocampal atrophy corresponds to prominent loss of episodic memory, it is likely that memory impairment is initially absent in hippocampal-sparing AD cases. Here, we report on a patient with an 8-year history of delusional jealousy with insidious onset who was clinically diagnosed as possible AD and pathologically confirmed to have AD with relatively preserved neurons in the hippocampus. This patient had delusional jealousy with a long pre-dementia stage, which initially was characterized by lack of memory impairment. Head magnetic resonance imaging findings showed preserved hippocampal volume with bilateral enlarged ventricles and mild-to-moderate cortical atrophy. Head single-photon emission computed tomography revealed severely decreased regional cerebral blood flow in the right temporal lobe. The resolution of the delusion was attributed to pharmacotherapy by an acetylcholinesterase inhibitor, suggesting that the occurrence of delusional jealousy was due to the disease process of AD. Although the neural basis of delusional jealousy remains unclear, this hippocampal-sparing AD case may be classified as an atypical presentation of AD.

Optimal treatment of Alzheimer's disease psychosis: challenges and solutions

Psychotic symptoms emerging in the context of neurodegeneration as a consequence of Alzheimer's disease was recognized and documented by Alois Alzheimer himself in his description of the first reported case of the disease. Over a quarter of a century ago, in the context of attempting to develop prognostic markers of disease progression, psychosis was identified as an independent predictor of a more-rapid cognitive decline. This finding has been subsequently well replicated, rendering psychotic symptoms an important area of exploration in clinical history taking - above and beyond treatment necessity - as their presence has prognostic significance. Further, there is now a rapidly accreting body of research that suggests that psychosis in Alzheimer's disease (AD+P) is a heritable disease subtype that enjoys neuropathological specificity and localization. There is now hope that the elucidation of the neurobiology of the syndrome will pave the way to translational research eventuating in new treatments. To date, however, the primary treatments employed in alleviating the suffering caused by AD+P are the atypical antipsychotics. These agents are approved by the US Food and Drug Administration for the treatment of schizophrenia, but they have only marginal efficacy in treating AD+P and are associated with troubling levels of morbidity and mortality. For clinical approaches to AD+P to be optimized, this syndrome must be disentangled from other primary psychotic disorders, and recent scientific advances must be translated into disease-specific therapeutic interventions. Here we provide a review of atypical antipsychotic efficacy in AD+P, followed by an overview of critical neurobiological observations that point towards a frontal, tau-mediated model of disease, and we suggest a new preclinical animal model for future translational research.

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.

Cerebral correlates of psychotic syndromes in neurodegenerative diseases

Psychosis has been recognized as a common feature in neurodegenerative diseases and a core feature of dementia that worsens most clinical courses. It includes hallucinations, delusions including paranoia, aggressive behaviour, apathy and other psychotic phenomena that occur in a wide range of degenerative disorders including Alzheimer's disease, synucleinopathies (Parkinson's disease, dementia with Lewy bodies), Huntington's disease, frontotemporal degenerations, motoneuron and prion diseases. Many of these psychiatric manifestations may be early expressions of cognitive impairment, but often there is a dissociation between psychotic/behavioural symptoms and the rather linear decline in cognitive function, suggesting independent pathophysiological mechanisms. Strictly neuropathological explanations are likely to be insufficient to explain them, and a large group of heterogeneous factors (environmental, neurochemical changes, genetic factors, etc.) may influence their pathogenesis. Clinico-pathological evaluation of behavioural and psychotic symptoms (PS) in the setting of neurodegenerative and dementing disorders presents a significant challenge for modern neurosciences. Recognition and understanding of these manifestations may lead to the development of more effective preventive and therapeutic options that can serve to delay long-term progression of these devastating disorders and improve the patients' quality of life. A better understanding of the pathophysiology and distinctive pathological features underlying the development of PS in neurodegenerative diseases may provide important insights into psychotic processes in general.

Frontotemporal atrophy associated with paranoid delusions in women with Alzheimer's disease

BACKGROUND

Paranoid delusions are a common and difficult-to-manage feature of Alzheimer's disease (AD). We investigated the neuroanatomical correlates of paranoid delusions in a cohort of AD patients, using magnetic resonance imaging (MRI) to measure regional volume and regional cortical thickness.

METHODS

113 participants with probable AD were assessed for severity of disease, cognitive and functional impairment. Presence and type of delusions were assessed using the Neuropsychiatric Inventory (NPI). Structural MRI images were acquired on a 1.5 T scanner, and were analyzed using an automated analysis pipeline.

RESULTS

Paranoid delusions were experienced by 23 (20.4%) of the participants. Female participants with paranoid delusions showed reduced cortical thickness in left medial orbitofrontal and left superior temporal regions, independently of cognitive decline. Male participants with delusions did not show any significant differences compared to males without delusions. An exploratory whole brain analysis of non-hypothesized regions showed reduced cortical thickness in the left insula for female participants only.

CONCLUSION

Frontotemporal atrophy is associated with paranoid delusions in females with AD. Evidence of sex differences in the neuroanatomical correlates of delusions as well as differences in regional involvement in different types of delusions may be informative in guiding management and treatment of delusions in AD.

Memory loss in Alzheimer's disease: implications for development of therapeutics

Alzheimer's disease (AD) is a progressive neurodegenerative disease marked by a constellation of cognitive disturbances, the earliest and most prominent being impaired episodic memory. Episodic memory refers to the memory system that allows an individual to consciously retrieve a previously experienced item or episode of life. Many recent studies have focused on characterizing how AD pathology impacts particular aspects of episodic memory and underlying mental and neural processes. This review summarizes the findings of those studies and discusses the effects of current and promising treatments for AD on episodic memory. The goal of this review is to raise awareness of the strides that cognitive neuroscientists have made in understanding intact and dysfunctional memory. Knowledge of the specific memorial processes that are impaired in AD may be of great value to basic scientists developing novel therapies and to clinical researchers assessing the efficacy of those therapies.

The many faces of psychosis in the elderly

PURPOSE OF REVIEW

As the population ages, the number of older patients with psychosis will greatly rise. This review focuses on the etiology, biologic and clinical findings, and treatments of common causes of psychosis in the elderly.

RECENT FINDINGS

Recent studies on psychosis related to Alzheimer's disease indicate that antipsychotic drugs have equivocal efficacy in improving psychotic symptoms and may have side effects or risks that outweigh their benefits. Behavioral interventions for agitation in dementia are showing some promise. In older adults with schizophrenia, intramuscular ziprasidone was found to be effective, and evidence is emerging for the use of hormone replacement therapy. For depression with psychosis, a recent study found that the combination of an antidepressant with an antipsychotic is no more effective than an antidepressant alone.

SUMMARY

There is support for the use of antipsychotic drugs for all types of psychosis in the elderly. While the atypical antipsychotics have a 'black box warning' on risk of death in elderly patients with dementia, the typical antipsychotics carry an even higher risk of death and adverse effects. Weighing the potential risks and benefits of treatment options is essential. Please refer to your country's regulations regarding the use of antipsychotic drugs.

The neurobiology of neuropsychiatric syndromes in dementia

PURPOSE OF REVIEW

Neuropsychiatric disturbances in dementia are prevalent, and research is uncovering their neurobiological correlates.

RECENT FINDINGS

Late-onset depression appears to be associated with Alzheimer's disease pathology at autopsy, and lifetime depression episodes may worsen Alzheimer's disease pathology in the hippocampus. Vascular disease and elevated homocysteine increase risk for both late-onset depression and Alzheimer's disease and may partly mediate their relationship. Monoamine changes are robust finding in Alzheimer's disease and may account for many observed depression symptoms. Risk of psychosis of Alzheimer's disease appears to be increased by several genes also implicated in schizophrenia (e.g., catechol-O-methyltransferase, neuregulin-1). Psychosis in dementia with Lewy bodies appears to be related to cholinergic deficits. Alzheimer's disease is associated with changes in the circadian sleep-wake cycles, including decreased night-time melatonin. Sleep apnea may be related to apolipoprotein E genotype and impact cognition in Alzheimer's disease. Rapid eye movement sleep behavior disorder is intricately related to synucleinopathies, such as dementia with Lewy bodies, but synuclein changes may not totally explain this relationship.

SUMMARY

Neuropsychiatric disturbances are a core feature of dementia and worsen many clinical outcomes. Among the most validated syndromes are depression, psychosis, and sleep disturbance of Alzheimer's disease. Neuropathology, neuroimaging, and genetic studies increasingly provide insight into the origins of these psychiatric symptoms in dementia.

Research agenda for DSM-V: diagnostic categories and criteria for neuropsychiatric syndromes in dementia

Neuropsychiatric symptoms in dementia represent a major health burden for older adults. These symptoms are often more distressing, impairing, and costly than cognitive symptoms in dementia, yet they have been less coherently categorized in the various versions of the Diagnostic and Statistical Manual of Mental Disorders (DSM). The preponderance of literature on psychiatric symptoms in dementia has been in patients with Alzheimer's disease. Diagnostic criteria have been proposed for psychosis, depression, and sleep disturbance in Alzheimer's disease. "Agitation" also appears to be a clinically important behavioral complication of dementia that warrants further study. Beginning with further validation of these proposed diagnostic criteria, future research can guide a more clinically meaningful description of these syndromes in DSM-V. Advancing biotechnology offers promise for discoveries related to the etiology and treatment of these syndromes. New research in this field should encompass diverse populations and different types of dementia. The high emotional and economic costs of neuropsychiatric symptoms in dementia implore diagnostic refinement to facilitate improved treatment.

Phenomenology and clinical correlates of delusions in Alzheimer disease

OBJECTIVES

The objectives of this study were to determine whether anosognosia, depression, and elevated mood are associated with delusions in Alzheimer disease (AD), and to examine the validity of standardized diagnostic criteria for psychosis of dementia.

METHOD

The authors assessed a consecutive series of 771 patients with AD attending a dementia clinic with a comprehensive neuropsychologic and psychiatric evaluation that included specific measures of delusions, hallucinations, anosognosia, depression, and elevated mood.

RESULTS

Delusions were found in one-third of the patients and hallucinations in 7%. Most patients with hallucinations also had delusions. A principal component analysis of the Psychosis Dementia Scale, which rates the presence and severity of delusions, produced the factors of paranoid misidentification and expansive delusions. Paranoid, but not expansive, delusions increased across the stages of the illness. Anosognosia and depression were significantly and independently associated with the presence of delusions, whereas elevated mood was significantly associated with expansive, but not paranoid, delusions. A multiple logistic regression analysis demonstrated that delusions in AD were significantly associated with depression, anosognosia, overt aggression, and agitation.

CONCLUSIONS

Anosognosia, depression, global cognitive deficits, and elevated mood are the main psychiatric correlates of paranoid misidentification and expansive delusions in AD, whereas overt aggression and agitation are the most frequent behavioral concomitants of psychosis in AD.

Cognitive neuroscience of delusions in aging

Assessments and clinical understanding of late-onset delusions in the elderly are inconsistent and often incomplete. In this review, we consider the prevalence, neurobehavioral features, and neuroanatomic correlations of delusions in elderly persons - those with documented cognitive decline and those with no evidence of cognitive decline. Both groups exhibit a common phenotype: delusions are either of persecution or of misidentification. Late-onset delusions show a nearly complete absence of the grandiose, mystical, or erotomanic content typical of early onset psychoses. Absent also from both elderly populations are formal thought disorders, thought insertions, and delusions of external control. Neuroimaging and behavioral studies suggest a frontotemporal localization of delusions in the elderly, with right hemispheric lateralization in delusional misidentification and left lateralization in delusions of persecution. We propose that delusions in the elderly reflect a common neuroanatomic and functional phenotype, and we discuss applications of our proposal to diagnosis and treatment.

Neuropsychological functioning and delusions in dementia: a pilot study

The present pilot study investigated the pattern of neuropsychological functioning associated with the presence of delusions in mild-to-moderate dementia. Participants, all of whom met criteria for dementia, were divided into two groups, delusional (n = 9) and non-delusional (n = 9). Individuals with hallucinations were excluded. Participants completed a neuropsychological test battery. Global cognitive functioning (MMSE) and behavioral disturbance (BEHAVE-AD) were also assessed. Differences between the delusional and non-delusional group were most marked for immediate recall of stories, which was higher in the non-delusional group. Scores on semantic fluency, attention (mental control), and overall cognitive functioning (MMSE) were also lower in the delusional group. Conversely, simple attention span (Digit Span) was within normal limits in both groups. Floor effects were noted on measures of delayed recall and alternating attention. This study supports previous findings of greater neuropsychological impairment in delusional as compared to non-delusional individuals with dementia. However, some areas of cognitive functioning may be relatively preserved. Future research should examine semantic processing in persons with dementia with and without delusions.

A Review of Rating Scales for Measuring Behavior Change Due to Frontal Systems Damage

OBJECTIVE

To perform a critical review of scales designed to measure frontal behavior change.

BACKGROUND

Changes in cognition due to frontal disease or damage have been well described, but noncognitive changes in behavior are often more deleterious functionally for frontal patients.

METHOD

The review concentrates on five behavior rating scales: the Behavior Rating Inventory of Executive Functions (BRIEF), the Dysexecutive Questionnaire (DEX), the Frontal Behavior Inventory (FBI), the Frontal Systems Behavior Scale (FrSBe), the Iowa Rating Scales of Personality Change (IRSPC), and the Neuropsychiatric Inventory (NPI). Other scales purporting to measure specific aspects of frontal functioning, but having less research support, are described briefly.

RESULTS AND CONCLUSIONS

The BRIEF and FrSBe have good reliability and large-scale norms. No norms are available for the other scales. The FrSBe and IRSPC have been shown to be valid in discriminating frontal from nonfrontal lesioned patients, but this has not been shown in the other scales. The FBI and NPI require trained raters, whereas the FrSBe, IRSPC, and BRIEF are administered to patients and/or family informants directly. The NPI and FBI are sensitive to certain changes in behavior attributed to frontal systems disruption but have been used primarily in dementia.

Review of delusions in dementia

Although delusions are common symptoms in dementia and are associated with a number of adverse outcomes, research in this area has been limited. This article attempts to summarize the existing literature on delusions in dementia with respect to known risk factors, etiology, pathogenesis, neurocognitive findings, behavioral symptoms, and treatment. This study reviews all relevant abstracts and articles pertaining to delusions and dementia. The reviewers found that the studies were limited by confusion concerning phenomenology. However, consistent findings show that delusions are associated with certain demographic variables, neuropathologic and neurocognitive findings, adverse behavioral outcomes, and limited treatment response. The authors conclude that further longitudinal studies with better clarification of terminology are required to clarify inconsistencies and shed light on future treatment options.