He sees and talks to people who aren't there. He then realizes that they weren't really there. His doctor says this is part of the dementia, but we're concerned. Hallucinations frequently occur with dementia. It's not clear if this means that the condition is worsening.
Most common dementias are degenerative and worsen over time.
In some cases, the hallucinations may help identify the type of dementia. In the last 10 years, understanding has increased of a dementia called Lewy body disease. In Lewy body disease, the dementia often includes hallucinations in association with signs and symptoms of Parkinson's disease, such as muscle rigidity, difficulty initiating movement and tremors. Rapid changes in the level of alertness may also be present. Hallucinations may also be a symptom of other types of dementia.