title: Psychiatric symptoms in frontotemporal dementia: epidemiology, phenotypes, and differential diagnosis.
abstract: Frontotemporal dementia (FTD) is the most frequently occurring dementia in the presenile population. Despite epidemiologic data showing that patients with FTD may have experienced previous psychiatric disorders and that patients with psychotic disorders may develop dementia more often than expected in the nonaffected population, the overlap between these two conditions has been underestimated. Nevertheless, the identification in recent years of several genetic causes of FTD associated with heterogeneous and atypical presentations, including pure psychiatric symptoms, has shifted scientific interest back to obtaining a better understanding of common mechanisms between FTD and psychotic disorders. We review the current knowledge of the FTD spectrum and common features shared by FTD and some psychiatric diseases, starting from Pick's clinical description of the disease, moving toward pathogenic aspects of the disease and genetic causes and associated phenotypes, and finishing with analysis of crossing borders between FTD and psychiatric disorders (mainly represented by schizophrenia and bipolar spectrum disorders) in clinical practice in terms of overlapping symptoms, differential diagnosis, comorbidity, and treatment issues.
authors.affiliation: Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy. Electronic address: daniela.galimberti@unimi.it.
authors.forename: Daniela
authors.initials: D
authors.lastname: Galimberti
authors.affiliation: Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy; Bipolar Disorders Clinic, Stanford University, Stanford, California.
authors.forename: Bernardo
authors.initials: B
authors.lastname: Dell'Osso
authors.affiliation: Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy.
authors.forename: A Carlo
authors.initials: AC
authors.lastname: Altamura
authors.affiliation: Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy.
authors.forename: Elio
authors.initials: E
authors.lastname: Scarpini
mesh_terms: D000328:Adult; D000368:Aged; D000073885:C9orf72 Protein; D003937:Diagnosis, Differential; D057180:Frontotemporal Dementia / Q000175:diagnosis / Q000453:epidemiology* / Q000235:genetics / Q000523:psychology*; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics; D008875:Middle Aged; D010641:Phenotype; D000077153:Progranulins; D011506:Proteins / Q000235:genetics; D016875:tau Proteins / Q000235:genetics
chemical_list: D000073885:C9orf72 Protein; C568651:C9orf72 protein, human; C492314:GRN protein, human; D036341:Intercellular Signaling Peptides and Proteins; C054369:MAPT protein, human; D000077153:Progranulins; D011506:Proteins; D016875:tau Proteins
keywords: Bipolar disorder (BD); Frontotemporal dementia (FTD); Frontotemporal lobar degeneration (FTLD); Pick dementia; Psychosis; Schizophrenia (SZ)