SummaryBruce Willis was diagnosed with frontotemporal dementia (FTD) in 2023, but his wife, Emma Heming Willis, was shocked by the first symptom that led to his diagnosis. FTD is often misdiagnosed as a mental health condition or as Alzheimer’s disease. Unlike Alzheimer’s, FTD typically develops at a younger age, usually between 40 and 65, though it can appear later in life as well. It accounts for approximately 10% to 20% of all dementia cases.