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

Psychosis risk as a function of age at onset: A comparison between early- and late-onset psychosis in a general population sample

This paper proposes a partial-order semantics for a stochastic process algebra that supports general (non-memoryless) distributions and combines this with an approach to numerically analyse the first passage time of an event. Based on an adaptation of McMillan's complete finite prefix approach tailored to event structures and process algebra, finite representations are obtained for recursive processes. The behaviour between two events is now captured by a partial order that is mapped on a stochastic task graph, a structure amenable to numerical analysis. Our approach is supported by the (new) tool FOREST for generating the complete prefix and the (existing) tool PEPP for analysing the generated task graph. As a case study, the delay of the first resolution in the root contention phase of the IEEE 1394 serial bus protocol is analysed

Case series with late-onset psychosis hospitalized in a geriatric psychiatry unit in Turkey: Experience in 9 years

In this article we report the first series of Turkish inpatients with late-onset psychosis, and describe our 9-year experience at the only inpatient geriatric psychiatry department in Turkey. Among 420 patients hospitalized between 1993 and 2002, 27 were psychotic. In this group, eight patients were diagnosed as having late-onset schizophrenia (LOS) and six very-late-onset schizophrenia-like psychosis (VLOSLP). Five patients had early-onset schizophrenia and eight had delusional disorder. Females were more frequently seen in the group with LOS and the group with VLOSLP. Except for one patient with LOS, all patients with VLOSLP and LOS had paranoid psychosis. Nihilistic delusions, delusions of poverty or guilt, thought withdrawal, thought insertion, and thought broadcasting were not seen in any of the patients. Additionally, none of the LOS or VLOSLP patients showed erotomanic delusions. Grandiose and mystic delusions were not seen in those with VLOSLP. Treatment results and antipsychotic dosages at discharge were similar to those in previous reports from other cultures