The Relationship Between Schizophrenia and Frontotemporal Dementia

1Department of Psychiatry and Behavioral Neuroscience, University of Chicago, Chicago, IL, USA.
Journal of Geriatric Psychiatry and Neurology (Impact Factor: 1.63). 06/2013; 26(3). DOI: 10.1177/0891988713490992
Source: PubMed

ABSTRACT Schizophrenia is a relatively common disorder diagnosed by the presentation of psychotic symptoms in the absence of identifiable neurologic or other organic cause. Frontotemporal dementia (FTD) is a relatively rare progressive neurodegenerative disorder that can present with a multitude of cognitive and behavioral symptoms including psychosis. At times, this phenotypic overlap can mean that schizophrenia and FTD are 2 possibilities in the differential diagnosis of a psychotic presentation. In this article, we systematically review the literature on the relationship between schizophrenia and FTD including case reports that highlight the potential for diagnostic confusion, clinical studies examining the relationship between the disorders, and the molecular evidence of shared pathophysiologic mechanisms. Although a relationship between the disorders is not definitively supported by the current literature, we identify the characteristics of a psychotic presentation that should alert the clinician to the possibility of FTD and describe the areas where further research is needed to clarify the pathophysiologic relationship.

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    ABSTRACT: Frontotemporal dementia (FTD) is a neurodegenerative disorder, associated with a progressive decline in behavior caused by focal degeneration of the frontal lobes. Psychosis was an underestimated symptom of FTD, however, recent genetic research has revealed a high prevalence of psychosis in certain genetic groups. The primary objective of this work is to review the literature on psychosis in FTD and to propose directions for future research, with reference to findings on psychosis in schizophrenia. A search was performed using PubMed, MEDLINE, and EMBASE. Search terms included "frontotemporal dementia", "psychosis", "schizophreni*", "psychotic symptoms", "hallucinations", and "delusions", and it identified 122 articles. Results revealed: 1) prevalence is approximately 10%, 2) TDP-43 type B and FUS pathologies might have relatively high frequency of psychosis, 3) psychosis in FTD is higher with genetic mutations of C9ORF72 and GRN, 4) imaging researches did not achieve conclusive results, and 5) no treatment for psychosis in FTD is currently available. A limitation of this systematic review is that it includes a small number of studies specifically examining psychosis in FTD. It is suggested that a possible overlap exists between FTD and schizophrenia. This potential overlap indicates a vulnerability to psychosis due to brain systems and pathways shared by these disorders.
    Journal of Alzheimer's disease: JAD 06/2014; 42(2). DOI:10.3233/JAD-140312 · 3.61 Impact Factor
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May 21, 2014