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Schizophrenia Bulletin Jul 2021
Topics: Adaptation, Psychological; Delusions; Humans; Male; Schizophrenia; Schizophrenic Psychology
PubMed: 33479761
DOI: 10.1093/schbul/sbaa189 -
BMC Neurology Mar 2024Neuropsychiatric symptoms and delusions are highly prevalent among people with dementia. However, multiple roots of neurobiological bases and shared neural basis of...
BACKGROUND
Neuropsychiatric symptoms and delusions are highly prevalent among people with dementia. However, multiple roots of neurobiological bases and shared neural basis of delusion and cognitive function remain to be characterized. By utilizing a fine-grained multivariable approach, we investigated distinct neuroanatomical correlates of delusion symptoms across a large population of dementing illnesses.
METHODS
In this study, 750 older adults with mild cognitive impairment and Alzheimer's disease completed brain structural imaging and neuropsychological assessment. We utilized principal component analysis followed by varimax rotation to identify the distinct multivariate correlates of cortical thinning patterns. Five of the cognitive domains were assessed whether the general cognitive abilities mediate the association between cortical thickness and delusion.
RESULTS
The result showed that distributed thickness patterns of temporal and ventral insular cortex (component 2), inferior and lateral prefrontal cortex (component 1), and somatosensory-visual cortex (component 5) showed negative correlations with delusions. Subsequent mediation analysis showed that component 1 and 2, which comprises inferior frontal, anterior insula, and superior temporal regional thickness accounted for delusion largely through lower cognitive functions. Specifically, executive control function assessed with the Trail Making Test mediated the relationship between two cortical thickness patterns and delusions.
DISCUSSION
Our findings suggest that multiple distinct subsets of brain regions underlie the delusions among older adults with cognitive impairment. Moreover, a neural loss may affect the occurrence of delusion in dementia largely due to impaired general cognitive abilities.
Topics: Humans; Aged; Alzheimer Disease; Delusions; Cognitive Dysfunction; Cognition; Brain
PubMed: 38448803
DOI: 10.1186/s12883-024-03568-5 -
BMC Psychiatry Dec 2023Patients with Alzheimer's disease (AD) often exhibit neuropsychiatric symptoms (NPS), particularly delusions. Previous studies have shown an association between white...
BACKGROUND
Patients with Alzheimer's disease (AD) often exhibit neuropsychiatric symptoms (NPS), particularly delusions. Previous studies have shown an association between white matter hyperintensities (WMH) and specific NPS. This study aims to explore the relationship between WMH volume and delusions in AD patients by comparing the WMH volumes of delusional and non-delusional subgroups.
METHODS
80 AD patients were divided into a delusion group (n = 36) and a non-delusion group (n = 44) based on the Neuropsychiatric Inventory (NPI). The brain cortical volume and WMH volume were quantitatively calculated for all 80 patients, including total WMH volume, periventricular WMH (PVWMH) volume, deep WMH volume, as well as bilateral frontal lobe, temporal lobe, parietal lobe, and occipital lobe WMH volumes. Firstly, we compared the differences in WMH volumes between the delusion group and non-delusion group. Then, within the delusion group, we further categorized patients based on severity scores of their delusional symptoms into mild (1 point), moderate (2 points), or severe groups (3 points). We compared the WMH volumes among these three groups to investigate the role of WMH volume in delusional symptoms.
RESULTS
There was a significant difference in left occipital lobe WMH volume between the delusion group and non-delusion group(P < 0.05). Within the delusion group itself, there were significant differences in overall WMH volume as well as PVWMH volume among patients with mild or severe levels of delusions(P < 0.05).
CONCLUSION
Left occipital lobe WMH volume may be associated with the occurrence of delusional AD patients, and the total volume of whole-brain WMH and PVWMH volume may affect the degree of severity of delusional symptoms.
Topics: Humans; Alzheimer Disease; White Matter; Temporal Lobe; Brain; Parietal Lobe; Magnetic Resonance Imaging
PubMed: 38057778
DOI: 10.1186/s12888-023-05420-5 -
Early Intervention in Psychiatry Dec 2022Thinking biases are posited to be involved in the genesis and maintenance of delusions. Persecutory delusions are one of the most commonly occurring delusional subtypes... (Review)
Review
AIM
Thinking biases are posited to be involved in the genesis and maintenance of delusions. Persecutory delusions are one of the most commonly occurring delusional subtypes and cause substantial distress and disability to the individuals experiencing them. Their clinical relevance confers a rationale for investigating them. Particularly, this review aims to elucidate which cognitive biases are involved in their development and persistence.
METHODS
MEDLINE, Embase, PsycINFO and Global Health were searched from the year 2000 to June 2020. A formal narrative synthesis was employed to report the findings and a quality assessment of included studies was conducted.
RESULTS
Twenty five studies were included. Overall, 18 thinking biases were identified. Hostility and trustworthiness judgement biases appeared to be specific to persecutory delusions while jumping to conclusions, self-serving attributional biases and belief inflexibility were proposed to be more closely related to other delusional subtypes. While the majority of the biases identified were suggested to be involved in delusion maintenance, hostility biases, need for closure and personalizing attributional biases were believed to also have aetiological influences.
CONCLUSIONS
These findings show that some cognitive biases are specific to paranoid psychosis and appear to be involved in the formation and/or persistence of persecutory delusions.
Topics: Humans; Delusions; Paranoid Disorders; Bias; Psychotic Disorders
PubMed: 35396904
DOI: 10.1111/eip.13292 -
BMJ Case Reports Apr 2021This is a case report of a middle-aged man with no psychiatric history who presented with severe anxiety and psychotic symptoms from COVID-19. Following his discharge...
This is a case report of a middle-aged man with no psychiatric history who presented with severe anxiety and psychotic symptoms from COVID-19. Following his discharge from intensive care unit, he was unable to sleep, was increasingly agitated and was observed hitting his head off the walls, causing haematomas. He remained highly anxious and developed paranoid delusions and auditory and tactile hallucinations, needing admission to a psychiatric ward. Treatment with antipsychotic medication gradually improved his symptoms in a few weeks. This case report highlights the new onset of psychosis due to COVID-19 infection. It demonstrates the importance of early identification and treatment of neuropsychiatric complications within an acute hospital setting. Furthermore, there is a need for research in this area to help in the prevention and treatment of such psychiatric complications due to COVID-19.
Topics: Antipsychotic Agents; COVID-19; Delusions; Humans; Male; Middle Aged; Psychotic Disorders; SARS-CoV-2; Treatment Outcome
PubMed: 33906867
DOI: 10.1136/bcr-2021-242538 -
Annals of Physical and Rehabilitation... Jun 2017This review article summarizes neuropsychological descriptions of abnormal body representations in brain-damaged patients and recent neuroscientific investigations of... (Review)
Review
This review article summarizes neuropsychological descriptions of abnormal body representations in brain-damaged patients and recent neuroscientific investigations of their sensorimotor underpinnings in healthy participants. The first part of the article describes unilateral disorders of the bodily self, such as asomatognosia, feelings of amputation, supernumerary phantom limbs and somatoparaphrenia, as well as descriptions of non-lateralized disorders of the bodily self, including Alice in Wonderland syndrome and autoscopic hallucinations. Because the sensorimotor mechanisms of these disorders are unclear, we focus on clinical descriptions and insist on the importance of reporting clinical cases to better understand the full range of bodily disorders encountered in neurological diseases. The second part of the article presents the advantages of merging neuroscientific approaches of the bodily self with immersive virtual reality, robotics and neuroprosthetics to foster the understanding of the multisensory, motor and neural mechanisms of bodily representations.
Topics: Agnosia; Alice in Wonderland Syndrome; Body Image; Brain Injuries; Delusions; Depersonalization; Hallucinations; Humans; Phantom Limb; Robotics; Virtual Reality
PubMed: 27318928
DOI: 10.1016/j.rehab.2016.04.007 -
Schizophrenia Research Jul 2020Sleep disturbance is a common clinical issue for patients with psychosis. It has been identified as a putative causal factor in the onset and persistence of psychotic... (Review)
Review
BACKGROUND
Sleep disturbance is a common clinical issue for patients with psychosis. It has been identified as a putative causal factor in the onset and persistence of psychotic experiences (paranoia and hallucinations). Hence sleep disruption may be a potential treatment target to prevent the onset of psychosis and reduce persistent psychotic experiences. The aim of this review is to describe developments in understanding the nature, causal role, and treatment of sleep disruption in psychosis.
METHOD
A systematic literature search was conducted to identify studies, published in the last five years, investigating subjective sleep disruption and psychotic experiences.
RESULTS
Fifty-eight papers were identified: 37 clinical and 21 non-clinical studies. The studies were correlational (n = 38; 20 clinical, 18 non-clinical), treatment (n = 7; 1 non-clinical), qualitative accounts (n = 6 clinical), prevalence estimates (n = 5 clinical), and experimental tests (n = 2 non-clinical). Insomnia (50%) and nightmare disorder (48%) are the most prevalent sleep problems found in patients. Sleep disruption predicts the onset and persistence of psychotic experiences such as paranoia and hallucinations, with negative affect identified as a partial mediator of this relationship. Patients recognise the detrimental effects of disrupted sleep and are keen for treatment. All psychological intervention studies reported large effect size improvements in sleep and there may be modest resultant improvements in psychotic experiences.
CONCLUSIONS
Sleep disruption is a treatable clinical problem in patients with psychosis. It is important to treat in its own right but may also lessen psychotic experiences. Research is required on how this knowledge can be implemented in clinical services.
Topics: Delusions; Hallucinations; Humans; Paranoid Disorders; Psychotic Disorders; Schizophrenia; Sleep
PubMed: 31831262
DOI: 10.1016/j.schres.2019.11.014 -
CNS Neuroscience & Therapeutics Jul 2018Organic or secondary psychosis can be seen in diverse conditions such as toxic/metabolic disorders, neurodegenerative disease, and stroke. Poststroke psychosis is a rare... (Review)
Review
Organic or secondary psychosis can be seen in diverse conditions such as toxic/metabolic disorders, neurodegenerative disease, and stroke. Poststroke psychosis is a rare phenomenon, but its study has significantly contributed to the understanding of delusion formation. The evidence from case studies of patients with focal strokes shows that delusions develop following unilateral damage of the right hemisphere. The majority of patients with right hemisphere stroke do not develop delusions however, and advanced neuroimaging analysis has elucidated why this symptom develops in only a small proportion. Lesions of the right lateral prefrontal cortex or lesions with connectivity to this area correlate with delusional beliefs in this subgroup. Studies of patients with primary psychosis, for example schizophrenia, or under the influence of the psychotogenic drug ketamine, also show abnormal function of this area in relation to the severity of their abnormal beliefs. The conclusion of these studies is that the right lateral prefrontal cortex is 1 hub in a neural network which includes the basal ganglia and limbic system and receives inputs from midbrain dopamine neurones. In patients with schizophrenia, or at risk of psychosis, dopamine is dysregulated and evidence suggests that faulty dopamine signaling is the precursor of delusion formation. It is therefore likely that the mechanism of delusion formation is the same in both primary and secondary psychosis. This is consistent with the mainstay of treatment of both conditions being antipsychotic medication. However, antipsychotic medication in people with cerebrovascular disease should be avoided if at all possible. This is because epidemiological studies have found that antipsychotic use is associated with an increased risk of stroke and will thus compound the possibility of a further cerebrovascular accident.
Topics: Animals; Biology; Delusions; Humans; Pathology
PubMed: 29766653
DOI: 10.1111/cns.12973 -
Sante Mentale Au Quebec 2019Context Psychotic disorders are severe mental disorders that can cause a loss of contact with reality. Along with positive symptoms (delusions and hallucinations), they... (Review)
Review
Context Psychotic disorders are severe mental disorders that can cause a loss of contact with reality. Along with positive symptoms (delusions and hallucinations), they also encompass many other dysfunctions, such as sleep problems, which themselves can cause great distress and impairment in patients. Objective To review current literature on the relationship between sleep disorders and psychosis, on the clinical impact of such a relationship, and the psychological treatment of sleep disorders in the context of psychosis. Method Narrative overview of the literature synthesizing the findings about the relationship between psychosis and sleep disorders, and the psychological treatment of the latter, retrieved from searches of computerized databases, hand searches, and authoritative texts. Results Evidence shows a bidirectional relationship between psychosis and sleep disorders. Despite many hypotheses involving genetics, hormones, or neuronal functions regarding the nature of this association, the exact mechanism remains elusive. However, sleep-related problems are an interesting therapeutic target to improve quality of life and psychotic symptoms and respond well to psychological interventions. Conclusion Patients with psychotic disorders can benefit from CBT for insomnia, given a few adaptations to existing protocols. Additional studies are necessary to determine which patients are most likely to benefit from such interventions and to clarify the relationship between psychosis and sleep disorders, and the clinical implications of them co-existing.
Topics: Delusions; Female; Hallucinations; Humans; Male; Middle Aged; Psychotic Disorders; Quality of Life; Sleep Wake Disorders
PubMed: 33270392
DOI: No ID Found -
Schizophrenia Bulletin Mar 2017Delusions, the fixed false beliefs characteristic of psychotic illness, have long defied understanding despite their response to pharmacological treatments (e.g., D2... (Review)
Review
Delusions, the fixed false beliefs characteristic of psychotic illness, have long defied understanding despite their response to pharmacological treatments (e.g., D2 receptor antagonists). However, it can be challenging to discern what makes beliefs delusional compared with other unusual or erroneous beliefs. We suggest mapping the putative biology to clinical phenomenology with a cognitive psychology of belief, culminating in a teleological approach to beliefs and brain function supported by animal and computational models. We argue that organisms strive to minimize uncertainty about their future states by forming and maintaining a set of beliefs (about the organism and the world) that are robust, but flexible. If uncertainty is generated endogenously, beliefs begin to depart from consensual reality and can manifest into delusions. Central to this scheme is the notion that formal associative learning theory can provide an explanation for the development and persistence of delusions. Beliefs, in animals and humans, may be associations between representations (e.g., of cause and effect) that are formed by minimizing uncertainty via new learning and attentional allocation. Animal research has equipped us with a deep mechanistic basis of these processes, which is now being applied to delusions. This work offers the exciting possibility of completing revolutions of translation, from the bedside to the bench and back again. The more we learn about animal beliefs, the more we may be able to apply to human beliefs and their aberrations, enabling a deeper mechanistic understanding.
Topics: Animals; Association Learning; Computational Biology; Delusions; Humans; Neurosciences; Uncertainty
PubMed: 28177090
DOI: 10.1093/schbul/sbw194