Background The behavioural variant of frontotemporal dementia (bvFTD) strongly resembles primary psychiatric disorders. Furthermore, a bvFTD mimic may occur, without neurodegenerative aetiology.
Aim To offer psychiatrist clinical tools for making or ruling out a bvFTD diagnosis.
Method To present the results of the first prospective cohort study on bvFTD patients and primary psychiatric patients. Results are discussed within the context of the international literature.
Results Frontotemporal atrophy on imaging confirms a suspected bvFTD diagnosis. Merely fulfilling the bvFTD clinical criteria, with or without frontotemporal hypometabolism on functional imaging, may also result from primary psychiatric disorders or the bvFTD-phenocopy syndrome. A high level of stereotypy, hyperorality, a low level of depressive symptoms, impaired social cognition or absent insight increases the probability of bvFTD. Biomarker or genetic tests and follow-up are recommended. Conclusions A bvFTD diagnosis should be made multidisciplinary. Without the confirmation of atrophy or genetics, great reserve in making the diagnosis is in place and careful analyses for psychiatric aetiologies is advised.