Live Science | David Cassidy Has Dementia: Here's What That Means Live Science Doctors diagnose dementia when people have impairments in at least 2 out of 5 core brain functions, according to the Alzheimer's Association. These five core functions are memory, communication and language, ability to focus, reasoning and judgment ... David Cassidy, dementia and his tragic family history Actor David Cassidy Reveals He Has Dementia: Complete List Of Symptoms Of Alzheimer's, Most Common Form Of ... Former 'Partridge Family' Star David Cassidy Reveals He Suffers From Dementia |