Alzheimer's disease (AD) and frontotemporal dementia (FTD) are the most common causes of presenile dementia. Diagnosis relies on clinical evaluation based on neurologic and neuropsychological performance. Neuroimaging, including single-photon emission computed tomography (SPECT) is often obtained for confirmation. The overlap of symptoms in initial presentation such as changes in mood, personality, and behaviour may difficult the differential diagnosis. The present report aims to describe the case of a 68 year old male, with no prior psychiatric history until the age of 66, when he was first admitted for hospitalization with the diagnosis of severe depressive episode without psychotic symptoms (ICD10 F32.2). Two years later he was hospitalized for the second time, Investigation led to the diagnosis of dementia. Diagnostic categorization was difficult in the absence of imaging results consistent with clinical presentation and therapeutic response to cholinesterase inhibitors.

To describe an atypical presentation of dementia and discuss the diagnosis and therapeutic response.

We performed a Clinical file review and a comprehensive MEDLINE database search.