Frontotemporal dementia (FTD) is a group of brain disorders that primarily affect the frontal and temporal lobes, which are responsible for personality, behavior, and language. Symptoms often include changes in social behavior, emotional responses, and difficulty with language. FTD typically occurs at a younger age than other types of dementia, often between 40 and 65 years old. There are several subtypes of FTD, including behavioral variant frontotemporal dementia and primary progressive aphasia. The exact cause of FTD is not fully understood, but it can be associated with abnormal protein deposits in the brain. Diagnosis usually involves clinical evaluation, neuroimaging, and sometimes genetic testing.