What Is Dementia-Related Psychosis?

There are multiple types of dementia, including Alzheimer's, Parkinson's, and Lewy body dementia, according to George Grossberg, M.D., professor and director of geriatric psychiatry at Saint Louis University School of Medicine in Missouri. In each case, psychosis refers to a specific set of visual and audio false perceptions.

When we talk about dementia-related psychosis, we're talking about an individual who has what we call a dementia like Alzheimer's disease or Lewy body dementia or stroke-related, so-called vascular dementia and so on, who is now beginning to experience psychotic symptoms. By psychotic symptoms, we're talking specifically about delusions, which are kind of firm, false, persistent beliefs that a person might have that kind of don't jive with our sense of reality and/or hallucinations, where usually they may be seeing things or imagining things or less commonly hearing things that you and I don't see and hear.

Then the question becomes, how common is this or how common are these symptoms against a background of dementia in general? In general, probably about a third, maybe between 30% and 40% of individuals sometime during the course of the dementia will experience the psychotic symptoms or what we call dementia-related psychotic symptoms.