Background: Psychotic major depression (PMD) and delusional misidentification syndromes (DMS) exhibit cognitive deficits. Since the P300 component of event-related potentials (ERPs) provides valuable information concerning cognition, we studied this component of ERPs in DMS and PMD patients.
Methods: Nine patients with DMS, 15 patients with PMD, and 11 healthy controls, matched for age, sex and educational level, were tested using the auditory P300 component of ERPs.
Results: Both patient groups showed significant reductions in P300 amplitude at the right frontal region, while DMS group showed significant attenuation of the P300 amplitude at the right parietal area. P300 latency was significantly prolonged in the central midline brain region in the DMS group.
Limitations: The smallness of the sample size and the hypothetical post-hoc assignation of psychological function to regional activation.
Conclusion: PMD and DMS patients may share similar psychophysiological alterations connected to the right frontal region, mediating automatic processes, while DMS are associated with dysfunction of effortful mechanisms and allocation of attentional resources involving the interhemispheric and right parietal circuitry.
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http://dx.doi.org/10.1016/S0165-0327(03)00136-8 | DOI Listing |
Cogn Neuropsychiatry
January 2025
Department of Sociology, Philosophy and Anthropology, University of Exeter, Exeter, UK.
Introduction: In this paper, we present a new way of thinking about what is going on in cases of Capgras delusion which is a more varied presentation than represented in the literature. We do this by reflecting on the fundamental nature of identification, and then draw some lessons from this for understanding misidentification in general and Capgras delusion cases in particular. What emerges, through the conceptual tool of "mental files", is a unified, yet pluralistic, account of delusional misidentification of the Capgras type.
View Article and Find Full Text PDFCureus
August 2024
Medical Education, Lakeland Regional Health, Lakeland, USA.
J Alzheimers Dis
September 2024
Department of Psychiatry, The Jikei University School of Medicine, Tokyo, Japan.
Background: Delusional ideations, one of neuropsychiatric symptoms (NPSs), are frequently shown in the long-term progression of Alzheimer's disease (AD), and comorbid with other NPSs including depression or agitation. Despite various types of delusional ideations, the comorbidity between each delusional ideation and depressive symptoms has not been discussed.
Objective: The present cross-sectional study is aimed at testing the hypothetical mechanism of comorbid pattern in AD.
J Sleep Res
February 2025
The Netherlands Institute for Neuroscience, Amsterdam, The Netherlands.
Sleepwalking and related parasomnias are thought to result from incomplete awakenings out of non-rapid eye movement (non-REM) sleep. Non-REM parasomnia behaviours have been described as unconscious and automatic, or related to vivid, dream-like conscious experiences. Similarly, some observations have suggested that patients are unresponsive during episodes, while others that they can interact with their surroundings.
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