Delusion Formation Research Articles

Increased memory confidence and delusions in Alzheimer’s disease: a preliminary study

ABSTRACT There is uncertainty about whether delusion formation in Alzheimer’s disease (AD) can be explained by false memories. “Metamemory,” the ability to self-evaluate memory and identify memory errors, is impaired in people with delusions in schizophrenia. Our objective was to investigate whether false memory and metamemory were associated with delusions in AD. Participants with mild AD, with and without delusions, completed a computerized word recognition task and a metamemory measure. Group differences were compared using independent-samples t-tests or Mann Whitney tests. Significant findings were explored through binary logistic regression modeling. Participants with delusions (n = 10) gave more high confidence responses, significantly so for correct responses; percentage of high confidence correct responses for those with delusions (mean (SD)) was 69.7% (31.0%) and for those without (n = 14) was 43.5% (29.9%); t 22 = -2.09, p = .049. This remained significant when sex was included in regression modeling; for each 1.0% increase in high confidence correct responses, participants were 5.4% more likely to have delusions (Exp(β) 1.054, 95% CI 1.007–1.105, p = .025). Findings provide tentative support for a link between metamemory and delusions in AD. This should be explored in a larger sample as it has potential implications for treatment.

Psychotic Arousal and the Psychopathology of Acute Schizophrenia: An Exploratory Study of the Experiential Emotional State in Acute Psychosis.

Background: Increasing research data suggest that the dysfunction of emotional brain systems may be an important contributor to the pathophysiology of schizophrenia. However, contemporary psychopathology consistently underestimates the role of emotions in the phenomenology of the disease. Psychotic arousal (PA) is a conceptually defined psychopathological construct aiming to portray the experiential emotional state of acute psychosis. The concept provides an explanatory model for the emergence of psychosis, and the formation and maintenance of delusions based on neurobiological models on the formation of core consciousness and subjectivity. This is the first exploratory study of the major assumptions, endorsed in the project summarized as follows: (1) psychotic arousal is a discrete state, eligible for investigation; (2) abnormal experiential feelings are an integral part of this state; and (3) the state is responsive to antipsychotic intervention during the first weeks of treatment. Methods: We developed the Psychotic Arousal Scale (PAS) accordingly, explored its first psychometric properties and tested its relation to other psychopathological measures. Fifty-five acute schizophrenia patients were evaluated with the PAS, the Positive and Negative Syndrome Scale, the Brown Assessment of Beliefs Scale, the Hamilton Anxiety Scale, and the Calgary Depression Scale. Cronbach α coefficients, t-test analysis, correlations and mixed linear regression models were applied for testing the internal reliability of the scale, associations between parameters and sensitivity to change in three time periods during therapeutic intervention. Results: The results of the study support that (PA) is eligible for investigation as a discrete psychopathological state. Abnormal experiential feelings are an integral part of this state, presenting high affinity with other affective measures; their degree of severity relates to the delusions' conviction and are amenable to antipsychotics early in treatment during the acute psychotic episode. Conclusions: The findings of this exploratory study are connotative of the presence of an emotional arousal permeated by abnormal experiential feelings during acute psychosis, largely overlooked by contemporary psychopathology.

A description of COVID-19 related delusional content in admissions to an acute psychiatric unit.

The COVID-19 pandemic had a profound global impact, affecting individuals, including those with mental illness, through early and widespread information dissemination. Although the neurobiological basis of delusions remains unclear, external stimuli and historical events are known to influence them. The pandemic provided a unique opportunity to explore this phenomenon. To determine the prevalence of COVID-19-related delusional content, among individuals presenting for treatment of psychosis during the peak of the COVID-19 pandemic and investigate associated clinical and demographic factors. Chris Hani Baragwanath Academic Hospital in-patient psychiatry department. Data were extracted retrospectively from adult psychiatric admissions spanning April to September 2020 on patients whose presenting complaints included delusions. Demographic factors, symptoms, psychiatric, medical and substance use history, and a documented Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) diagnosis by the attending psychiatrist were collected. The prevalence of COVID-19-related delusional content was 25.5%. Significant demographic association was observed with education level of Grade 12 and above (p = 0.000338). The odds of a diagnosis of schizophrenia and related disorders were 2.72 times greater than mood and psychotic disorder due to another medical condition in those with COVID- 19-related delusional content (OR 2.19, 95% CI: [1.4-3.4]). The presence of COVID-19-related delusional content in patients admitted to hospital with psychosis provides further evidence of the role of external stimuli in the formation of delusions. This study underscores the influence of socio-cultural factors on delusions and advocates for interventions and expanded research to address mental health outcomes.

Delusions and the Predictive Mind

ABSTRACT A growing number of studies in both the scientific and the philosophical literature have drawn on a Bayesian predictive processing framework to account for the formation of delusions. The key here is that delusions form because of disrupted prediction error signalling. Parrott’s recent critique argues that the framework is incomplete in two respects: (i) it leaves unclear why delusional hypotheses are selected over none at all, or over more plausible alternatives; and (ii) it leaves unclear how exactly it is that delusional hypotheses are generated in the first place. In this paper, we defend the framework’s explanatory power by way of showing how it can go a long way in helping disentangle these concerns. We take up each of them in turn. As for the first, our argument turns on two claims: (a) believing nothing, although possible in principle, may not be a viable procedure in the circumstances; and (b) alternative hypotheses may be rendered unavailable for selection, due to aberrant prediction errors. As for the second concern, we distinguish three ways in which delusional hypotheses may be initially acquired, all of which are based on experience broadly construed.

Older people living in the community with delusion.

This study explores the intricate relationship between social interactions and the development of persecutory delusions among older women living alone in Japan. Focusing on the unique perspective of individuals experiencing delusions outside clinical settings, the aim was to understand the impact of interpersonal interactions on delusion formation. Cases of older women living alone with persecutory delusions were selected from records of municipal psychogeriatric services and medical consultations within a community space. This study employed a descriptive approach to propose a hypothesis regarding the possible connection between social interactions and the development of persecutory delusions within this demographic. Two relevant cases were identified, from which a three-step hypothesis emerged regarding the potential link between social interactions and the development of persecutory delusions in this demographic. Insights from these cases suggest that anxiety can trigger hallucinations, which, when unaddressed, evolve into delusional interpretations. Addressing these unmet needs could mitigate the progression of persecutory delusions. The findings of this study underline the critical relationship between social interactions and persecutory delusions among older women living alone. The unmet need for empathy influences the progression from anxiety-driven hallucinations to fully formed delusions. Early intervention can prevent the escalation of delusions and involuntary psychiatric hospitalization. This study underscores the importance of recognizing the link between social isolation and delusion emergence. It advocates for compassionate environments to meet the psychological needs of older individuals grappling with delusions. Geriatr Gerontol Int 2024; 24: 118-122.

The role of culture on the phenomenology of hallucinations and delusions, explanatory models, and help-seeking attitudes: A narrative review.

Culture has been posited to be involved in the formation and maintenance of delusions and hallucinations. The extent of these differences and how they affect explanatory models of psychosis and help-seeking attitudes remains to be understood. This review aims to present a cultural formulation to account for psychosis onset, symptom maintenance, and help-seeking attitudes. A narrative review was conducted to summarize the existing evidence base regarding cross-cultural differences in hallucinatory and delusional prevalence, explanatory models, and help-seeking attitudes in First Episode Psychosis (FEP) and Non-FEP Schizophrenia samples. Sixteen studies were eligible for inclusion. In terms of positive symptom specificity, cross-cultural differences were found. Specifically, auditory and visual hallucinations occurred most frequently in African patients, persecutory and grandiose delusions occurred at higher rates in African, Pakistani, and Latino patients, while delusions of reference were most prevalent in White-British groups. Three explanatory models were identified. Westerners tended to endorse a bio-psychosocial explanation, which was associated with increased help-seeking, engagement, and positive medication attitudes. Asian, Latino, Polish, and Māori patients endorsed religious-spiritual explanatory models, while African patients opted for a bewitchment model. The religious-spiritual and bewitchment models were associated with a longer duration of untreated psychosis (DUP) and poorer engagement with mental health services. These findings highlight the important influence of culture in the formation and maintenance of positive symptoms of psychosis, engagement, and help-seeking attitudes across different ethnic groups. The incorporation of cultural beliefs in formulation development could facilitate enriched CBTp practices and improved engagement amongst different cultural groups with Early Intervention Services.

Association Between False Memories and Delusions in Alzheimer Disease

Understanding the mechanisms of delusion formation in Alzheimer disease (AD) could inform the development of therapeutic interventions. It has been suggested that delusions arise as a consequence of false memories. To investigate whether delusions in AD are associated with false recognition, and whether higher rates of false recognition and the presence of delusions are associated with lower regional brain volumes in the same brain regions. Since the Alzheimer's Disease Neuroimaging Initiative (ADNI) launched in 2004, it has amassed an archive of longitudinal behavioral and biomarker data. This cross-sectional study used data downloaded in 2020 from ADNI participants with an AD diagnosis at baseline or follow-up. Data analysis was performed between June 24, 2020, and September 21, 2021. Enrollment in the ADNI. The main outcomes included false recognition, measured with the 13-item Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-Cog 13) and the Rey Auditory Verbal Learning Test (RAVLT) and volume of brain regions corrected for total intracranial volume. Behavioral data were compared for individuals with delusions in AD and those without using independent-samples t tests or Mann-Whitney nonparametric tests. Significant findings were further explored using binary logistic regression modeling. For neuroimaging data region of interest analyses using t tests, Poisson regression modeling or binary logistic regression modeling and further exploratory, whole-brain voxel-based morphometry analyses were carried out to explore the association between regional brain volume and false recognition or presence of delusions. Of the 2248 individuals in the ADNI database, 728 met the inclusion criteria and were included in this study. There were 317 (43.5%) women and 411 (56.5%) men. Their mean (SD) age was 74.8 (7.4) years. The 42 participants with delusions at baseline had higher rates of false recognition on the ADAS-Cog 13 (median score, 3; IQR, 1 to 6) compared with the 549 control participants (median score, 2; IQR, 0 to 4; U = 9398.5; P = .04). False recognition was not associated with the presence of delusions when confounding variables were included in binary logistic regression models. An ADAS-Cog 13 false recognition score was inversely associated with left hippocampal volume (odds ratio [OR], 0.91 [95% CI, 0.88-0.94], P < .001), right hippocampal volume (0.94 [0.92-0.97], P < .001), left entorhinal cortex volume (0.94 [0.91-0.97], P < .001), left parahippocampal gyrus volume (0.93 [0.91-0.96], P < .001), and left fusiform gyrus volume (0.97 [0.96-0.99], P < .001). There was no overlap between locations associated with false recognition and those associated with delusions. In this cross-sectional study, false memories were not associated with the presence of delusions after accounting for confounding variables, and no indication for overlap of neural networks for false memories and delusions was observed on volumetric neuroimaging. These findings suggest that delusions in AD do not arise as a direct consequence of misremembering, lending weight to ongoing attempts to delineate specific therapeutic targets for treatment of psychosis.

Obstructive Sleep Apnea, Psychotic Symptoms Common in Alzheimer’s Disease Patients

Obstructive Sleep Apnea, Psychotic Symptoms Common in Alzheimer’s Disease Patients

Ontological Adaptation in Transition to Adulthood: A Theoretical Framework for Integrating Phenomenology and Neuroscience in Psychosis Research.

In this theoretical review, the neurodevelopmental model of psychotic disorders is considered within the framework of ontological development, referring to the individual-level construction of a sense of reality regarding identity and worldview. Following Erikson's theory of development, the challenge of forging a personal and social identity is a developmental process typical of late adolescence and early adulthood. Accompanying this process is a developmentally normal increase in exploratory and risk-taking behavior, which sometimes includes challenging and defying cultural norms. Although many aspects of ontological adaptation are developmentally appropriate, we argue that psychopathology such as psychosis can be rooted in an abnormal deviation of this process, in which aberrant salience accelerates the typical drive to develop a meaningful sense of identity, leading to delusion formation. By placing psychosis onset within a broader context of normal development, this model offers a humanistic approach for understanding experiences of new onset of psychotic disorders.

Penerapan Art Therapy Terhadap Kemampuan Pasien Mengontrol Halusinasi pada Asuhan Keperawatan Pasien dengan Halusinasi Pendengaran di Rumah Sakit Umum Madani Palu

&#x0D; &#x0D; &#x0D; &#x0D; Background: Mental disorders are psychological or behavioral disorders that occur in a person, generally associated with affective, behavioral, cognitive and perceptual disorders. Schizophrenic patients have symptoms including thought process disorders, affective and emotional disorders, volitional disorders, psychomotor disorders and secondary symptoms in the form of delusions and hallucinations. Hallucinations are one of the symptoms of mental disorders where the client experiences changes in sensory perception, feels false sensations in the form of sound, sight, taste, touch or smell. The client feels a stimulus that is not actually there. Schizophrenia is a major disorder in thought processes and disharmony between thought processes, affect and emotions. Schizophrenia has the main symptom of decreased sensory perception, namely hallucinations. Destination : To apply Art Therapy to the Nursing Care of Patients with Auditory Hallucinations at Madani Hospital Palu. Research methods : Descriptive Research with Case Study approach. Measuring instrument : The measuring instrument used to relieve auditory hallucinations is using an observation sheet. Research result : It was found that the patient's complaint during the assessment was that the patient looked restless, often paced back and forth the patient said he heard whispering sounds like he wanted to scold people, the patient said the voice came when the patient was alone and before going to sleep. with nursing diagnoses Auditory hallucinations. The nursing intervention carried out a strategy for implementing auditory hallucinations, namely training how to rebuke, converse, doing activities, one of which was Art Therapy, taking medication regularly. Suggestion :Conclusion: The application of Art Therapy can control hallucinations at Madani Hospital Palu. Suggestion : It is hoped that nurses can apply Art Therapy to patients who experience hallucinations.&#x0D; &#x0D; &#x0D; &#x0D;

How Things Take Up Space: A Grounded Theory of Presence and Lived Space

In cognitive science, it is unclear what precisely presence (both in the sense of objecthood and immersion) refers to in lived experience. The present study addresses the research question of what the relationship between presence is and lived space. A hundred and seventeen phenomenological interviews were conducted with 14 participants. We sampled their experience in a transdiagnostic manner. That is, we observed how the experience of presence changes both in circumstances appraised as positive (e.g., sexual intimacy) and negative (e.g., psychopathology). Our grounded theory suggests that presence is a phenomenon that is comprised of all available sensory knowledge, however, it itself is not present in any one sensory modality. Presence takes the form of a disembodied sense of solidity. Our findings can be related to the notion of transmodality in contemporary qualitative phenomenology (i.e., the idea that there are some aspects of experience that can be readily translated from one sensory modality to another. Further, how presence (in its capacity as immersion) is related to lived space can shed further light on the formation of delusions, suggesting that it is based on sensory alterations rather than changes in belief. Finally, the observation that presence as it appears in lived space need not perfectly correspond to the objective situation, can elucidate extant discussion on whether presence is an amodal aspect of consciousness.

Accuracy of immediate self-assessment of neurocognitive test performance: Associations with psychiatric diagnosis and longitudinal psychotic symptoms

Participants with schizophrenia (SCZ) and bipolar disorder (BD) have challenges in self-evaluation of their cognitive and functional abilities, referred to as introspective accuracy (IA). Although psychotic symptoms are commonly found to be uncorrelated with cognitive performance, many models of the development of delusions focus on failures in self-assessment and responses biases during momentary monitoring. We performed a single 4-test cognitive assessment on 240 participants (schizophrenia n = 126; bipolar disorder n = 114) and asked them to make a judgment about their performance immediately after completion of each task. We related performance and these judgments to results of Ecological Momentary Assessments (EMA) of the momentary occurrence of psychotic symptoms (Voices, paranoid ideas, other delusions) collected over up to 90 surveys over a 30 days prior to the single cognitive assessment. We examined test performance and the accuracy of self-assessment at that assessment, looking at diagnostic differences in performance and mis-estimation of performance. Participants with bipolar disorder had better cognitive performance, but there were no differences in mis-estimation. Analyses of the correlation between cognitive performance and self-assessment were all significant and better cognitive performance predicted reduced errors in self-assessment. Examination of the 30-day course of psychotic symptoms and IA could only be performed in participants with schizophrenia, revealing correlations between more common occurrences of all three psychotic symptoms and increased absolute values for IA errors. These data are consistent with theories of cognitive response biases and the formation of delusions.

Translating affective and cognitive mechanisms of psychotic symptoms into better therapies

For a long time, psychotic symptoms were seen as too different from normal experiences to be explicable by psychological theories, let alone modifiable by psychological therapy. In the 1990s, the epidemiological research pointing to a continuum of psychotic symptoms and the clinical success in using cognitive approaches for psychosis strongly challenged this view. This inspired the field – along with my own work – to focus on a better understanding of the psychological mechanisms of psychotic symptoms in order to develop increasingly effective interventions. Together with other researchers, I have found that negative affect and aberrant arousal play a crucial role in the formation of delusions where they appear to interact with more fundamental problems in belief updating. While our understanding of the basic mechanisms that drive psychotic symptoms is gaining precision, the challenge remains to find the most suitable ways of targeting these mechanisms.

'An experience of meaning': A 20-year prospective analysis of delusional realities in schizophrenia and affective psychoses.

Delusions are transdiagnostic and heterogeneous phenomena with varying degrees of intensity, stability, and dimensional attributes where the boundaries between everyday beliefs and delusional beliefs can be experienced as clearly demarcated, fuzzy, or indistinguishable. This highlights the difficulty in defining delusional realities. All individuals in the current study were evaluated at index and at least one of six subsequential follow-ups over 20 years in the Chicago Longitudinal Study. We assessed 16 distinct delusions categorized as thought or thematic delusions. We also examined the probability of recurrence and the relationships between delusions and hallucinations, depression, anxiety, and negative symptoms. The sample consisted of 262 individuals with schizophrenia vs. affective psychosis. Thought delusions were significantly different between groups at all follow-up evaluations except the 20-year timepoint. Thematic delusions were more common than thought delusions and show a significant decreasing pattern. In general, delusional content varied over time. Referential, persecutory, and thought dissemination delusions show the highest probability of recurrence. Hallucinations were the strongest indicator for thought, thematic, and overall delusions. The formation and maintenance of delusions were conceptualized as a multimodal construct consisting of sensory, perceptual, emotional, social, and somatic embodiment of an “experience of meanings”. Given the significant associations between delusions and hallucinations, future work incorporating participatory research is needed to better define and align subjective and objective perspectives. Our research also points to the need for future clinical interventions that specifically evaluate and target the coexistence and entanglement of delusions and hallucinations.

Précis of Delusions and Beliefs: A Philosophical Inquiry

The central hypothesis of this book, Delusions and Beliefs: A Philosophical Inquiry (Routledge, 2019), is that delusions are malfunctional beliefs (Chapter 1); they belong to the category of belief (Chapter 2) but, unlike mundane false or irrational beliefs, they fail to perform some functions of belief (Chapter 3). More precisely, delusions directly or indirectly involve some malfunctioning cognitive mechanisms, which is empirically supported by the two-factor account of delusion formation (Chapter 4).

The concept of psychotic arousal and its relevance to abnormal subjective experiences in schizophrenia. A hypothesis for the formation of primary delusions

The presence of abnormal subjective experiences in the prodromal stages of schizophrenia as well as their contribution to delusional formation have been highlighted in psychiatric literature, but their nature and their involvement in the transition and establishment of full-blown psychosis remains elusive. In this paper, we venture to form a coherent hypothesis for the formation of primary delusions by attributing importance to the emotional and affective symptoms experienced by patients during the acute state of psychosis. We underline the presence of abnormal subjective experiences described as ‘feelings’ in patients’ narratives, their co-occurrence with discernible emotional manifestations and symptoms, and their rather simultaneous retreat from the clinical picture shortly after the effective administration of antipsychotic treatment. We further distinguish them from their enveloping thought content, on the base of their different course pattern and natural characteristics. We argue that this composite emotional picture – which we call “psychotic arousal” – though resembling the acknowledged “delusional mood”, traverses the acute state of psychosis to a greater extent and intensity, as long as we observe delusions flourishing and expanding. We specifically suggest that altered subjective experiences can be seen as emotional in nature and best described as “experiential feelings”. Consequently, we reflect upon neuroscientific theories and models supporting a layered concept for the formation of consciousness that attribute a paramount role on emotions as a representation of neural maps of the material body’s state. We explore patients’ “experiential feelings” as the morbid outcome of an otherwise normal process and we provide a theoretical solution for the psychotic transition and the formation of primary delusions. Our hypothesis, eventually, responds to long-standing questions regarding the content of the delusions, their abrupt appearance, their self-referential character, their selectivity and specificity, as well as their impact on awareness and the erroneous deployment of extended consciousness. We suggest that further enquiry of the proposed hypothesis could elucidate more deeply the phenomenology of schizophrenia and benefit both psychopathology and neuroscience of self.

Capgras Syndrome and Other Delusions of Misidentification: Integrating Neuropsychological Models of Delusion Formation with Psychoanalytic Object-Relations Theory

Capgras Syndrome and Other Delusions of Misidentification: Integrating Neuropsychological Models of Delusion Formation with Psychoanalytic Object-Relations Theory

Jumping to Conclusions and Its Associations With Psychotic Experiences in Preadolescent Children at Familial High Risk of Schizophrenia or Bipolar Disorder-The Danish High Risk and Resilience Study, VIA 11.

The jumping to conclusions (JTC) bias, ie, making decisions based on inadequate evidence, is associated with psychosis in adults and is believed to underlie the formation of delusions. Knowledge on the early manifestations of JTC and its associations with psychotic experiences (PE) in children and adolescents is lacking. Preadolescent children (mean age 11.9 y, SD 0.2) at familial high risk of schizophrenia (FHR-SZ, n = 169) or bipolar disorder (FHR-BP, n = 101), and controls (n = 173) were assessed with the Beads Task to examine JTC. The number of beads drawn before making a decision, "draws to decision" (DTD) was used as a primary outcome. PE were ascertained in face-to-face interviews. General intelligence was measured with Reynolds Intellectual Screening Test. Children at FHR-SZ took fewer DTD than controls (4.9 vs 5.9, Cohen's d = 0.31, P = .004). Differences were attenuated when adjusting for IQ (Cohen's d = 0.24, P = .02). Higher IQ was associated with a higher number of DTD (B = 0.073, P < .001). Current subclinical delusions compared with no PE were associated with fewer DTD in children at FHR-SZ (P = .04) and controls (P < .05). Associations between delusions and DTD were nullified when accounting for IQ. JTC marks familial risk of psychosis in preadolescence, not reducible to general intelligence. JTC is associated with subclinical delusions, but this may be an expression of intellectual impairment. Future studies should establish temporality between JTC and delusion formation and examine JTC as a target for early intervention.

Against a second factor

In his recent book Delusions and Beliefs, Kengo Miyazono offers a thoroughgoing defence of delusions as biologically malfunctioning beliefs, greatly elaborating on his earlier (2015) defence of this view. Miyazono has it that delusions have biological doxastic functions (i.e. functions specific to belief), and that delusions involve direct or indirect malfunctions of this kind. In this short piece, I focus on Miyazono’s defence of a two-factor approach to delusion formation as it appears in Chapter Four (Etiology). Miyazono approaches his discussion of the debate between one- and two-factor theories having already defended the key thesis of the book: that delusions are malfunctioning beliefs. Of course, that thesis might be thought to mesh nicely with the two-factor theorist’s claim that there is a cognitive abnormality present in delusion formation or maintenance. However, I will discuss Miyazono’s defence of the two-factor position in isolation from its role in his overall account of delusion. Miyazono abstracts away from the particulars of Max Coltheart’s two-factor view, and takes himself to be investigating the plausibility of two-factor theories without the specific commitments of Coltheart’s view (i.e. that the first factor of the Capgras delusion is not consciously accessible, and that the second factor is related to right hemisphere abnormalities). Miyazono also captures under the two-factor heading theories which locate the second factor in belief maintenance rather than just in belief formation. He puts forward a new argument for a two-factor approach which goes via inference to the best explanation. I begin by arguing that Miyazono’s starting motivation for a two-factor approach rests on a misrepresentation of the one-factor approach. Then, I turn to the four components of Miyazono’s inference to the best explanation argument, and argue that in each case, we do not have grounds for positing a second factor.

Neuropathological studies of serotonergic and noradrenergic systems in Lewy body disease patients with delusion or depression.

AimThe association between psychiatric symptoms in Lewy body disease (LBD) and the noradrenergic and serotonergic systems is still controversial. This study investigated the quantitative relationships of depression and delusion with these systems.MethodsWe studied 24 postmortem tissues from individuals with a pathological diagnosis of LBD with sufficient clinical history. The numbers of neurons and Lewy bodies (LBs) in the locus coeruleus (LC) and dorsal raphe nucleus (DRN) were counted, and the density of neurons in the DRN was analyzed. In addition, the densities of tryptophan hydroxylase‐positive neurites and norepinephrine transporter‐positive neurites in the amygdala and dorsal prefrontal cortex were measured. Finally, we divided the cases into two groups: with or without depressive mood, and with or without delusion. Quantitative histological data were compared between the groups.ResultsThe group with depressive mood had a significantly smaller number of neurons in the LC compared with the group without depressive mood. The group with delusion had a significantly larger number of LBs in the DRN compared with the group without delusion. The density of norepinephrine transporter‐positive neurites in the dorsal prefrontal cortex was significantly correlated with the number of neurons in the LC.ConclusionsThe accumulation of LBs in the DRN of individuals with LBD was associated with delusion, whereas a decrease in the number of neurons in the LC was associated with depressive mood. These neurodegenerative changes involved the serotonergic and noradrenergic systems and may be associated with the formation of delusion and depression, respectively, in LBD.