International Review of Psychiatry, April 2013; 25(2): 168-177 Schizophrenia and frontotemporal dementia: Shared causation? MICHAL HARCIAREKI, DOLORES MALASPINA2, TAO SUN' & ELKHONON GOLDBERG' 'Division of Clinical Psydtokgy and Neuropsydrology, Institute of Psychology, University of Gdansk, Poland, 2Depar:ment of Psychiatry, New York University School of Medicine, Newlbrk, USA, 3Department of Cell and Developmental Biology, Cornell University Will Medical College, New York, USA, 4Depanmmt of Neurology, New York University School of Medicine, New York, USA informa healthcare Abstract The relationship between specific genes and particular diseases in neuropsychiatry is unclear, and newer studies focus on shared domains of neurobiological and cognitive pathology across different disorders. This paper reviews the evidence for an association between schizophrenia and frontotemporal dementia, including symptom similarity, familial co-morbidity, and neuroanatomical changes. Genetic as well as epigenetic findings from both schizophrenia and frontotemporal demen- tia are also discussed. As a result, we introduce the hypothesis of a shared susceptibility for certain subgroups of schizo- phrenia and frontotemporal dementia.This common causation may involve the same gene(s) at different stages of life: early in schizophrenia and late in frontotemporal dementia. Additionally, we provide a rationale for future research that should emphasize both genetic and cognitive parallels between certain forms of schizophrenia and frontotemporal dementia in a synergistic, coordinated way, placing both in the context of aberrant lateralization patterns. Introduction The relationship between specific genes and particu- lar diseases in neuropsychiatry remains unclear, and the understanding of this relationship continues to evolve, reflecting the changes in the neuroscientific zeitgeist. Variable expressivity, plciotrophic effects, partial penetrancc, cpistasis, and gene—