A disorder that affects memory, language and personality, dementia rarely occurs in people under the age of 60, according to MedlinePlus. As dementia progresses, patients can have signs of psychosis, in which they have a break with reality. Drs. Abi V. Rayner, James G. O'Brien and Ben Schoenbachler, authors of the article “Behavior Disorders of Dementia: Recognition and Treatment,” point out that 15 to 75 percent of patients with Alzheimer's disease, a type of dementia, have psychosis. The symptoms of psychosis can affect a patient's behavior.
Visual Hallucinations
Patients with dementia can start having hallucinations when they have psychosis. Rayner, O'Brien and Schoenbachler note that dementia patients tend to have visual hallucinations, in which they see something that is not real. For example, patients may see animals in the room. Some patients may see people in their visual hallucinations. The authors explain that these hallucinations usually do not frighten or upset patients, so they may not need treatment. The Merck Manual Home Edition points out that hallucinations differ from illusions, which can also occur with dementia. With an illusion, a patient mistakes something she sees, like a shadow, for something else, like an animal.
Delusions
Another sign of psychosis in dementia patients is delusions, which are false beliefs. Delusions in dementia patients fall into two categories: dementia with paranoia, and dementia without paranoia. The Merck Manual Home Edition explains that people may confuse dementia without paranoia with disorientation, but they differ on the how the patient answers. For example, when a dementia patient has a delusion without paranoia, he may say that the hospital is his house and continues to say so. But with disorientation, the patient says that the hospital is a different place each time asked, like a store or a hotel, because he does not know where he is. When a dementia patient has delusions with paranoia, he becomes fearful. For example, the patient may say that his caretaker is trying to kill him.
Delusional Misidentification
Rayner, O'Brien and Schoenbachler explain that delusional misidentification, in which patients mistake objects or people for something else, results from problems with cognition and vision. For example, when a patient sees her family, she may not believe that they are really her family. She may accuse them of being strangers who entered her house. While cognitive decline contributes to delusional misidentification, the problem with confusing family members with imposters differs from the complete memory loss that advanced dementia patients have. In the latter cases, patients cannot identify their family members due to severe memory problems. Delusional misidentification can also affect the patient when identifying herself, such as in a photograph.
Agitation
Along with the delusions and hallucinations, dementia patients can become agitated. The Merck Manual Professional Edition points out that doctors use the Cohen-Mansfield Agitation Inventory to classify patients' behavior into one of four categories: verbally aggressive, verbally non-aggressive, physically aggressive, or physically non-aggressive. For example, verbally aggressive behavior involves cursing and temper outbursts, while verbally non-aggressive behavior involves complaining and interrupting. The Cohen-Mansfield Agitation Inventory defines physical aggressive behavior as hitting and biting, and physically non-aggressive behavior as hiding things and undressing at inappropriate times.
References
- Merck Manual Professional Edition: Behavioral and Psychological Symptoms of Dementia
- MedlinePlus Medical Encyclopedia: Dementia
- “American Family Physician”; Behavior Disorders of Dementia: Recognition and Treatment; Abi V. Rayner, MD, MPH, James G. O'Brien, MD and Ben Schoenbachler, MD; February 2006
