Dementia-Related Psychosis
Scientist Explains with Dr. Corinne Fischer
October 19, 2022
What is dementia-related psychosis?
Dementia-related psychosis (DRP) refers to psychotic symptoms that occur in the context of a neurodegenerative disease (e.g., Alzheimer’s disease). Neurodegenerative diseases cause changes in the brain, which are linked to the expression of psychotic symptoms.
Delusions and hallucinations are common forms of DRP. There are different types of delusions, but misidentification and persecutory delusions are most commonly seen. In a misidentification delusion, someone known to the person living with dementia is replaced by an imposter. Or, someone’s identity is confused – for example, a person’s son is confused for their husband. In a persecutory delusion, the person living with dementia is being wronged by someone. For example, misplacing something is attributed to a theft. Hallucinations are when a person living with dementia has a sensory experience they believe to be real, but it exists only in their mind. For example, they may see shadows or images of threatening people or things.
How common is dementia-related psychosis?
Approximately one-third of people living with neurodegenerative diseases will experience DRP. Dementia-related psychosis can occur any time throughout the progression of someone’s disease; however, it is most commonly seen in the middle stages. Exceptions include Lewy body dementia and Parkinson’s disease dementia, where psychotic symptoms can occur very early on.
Why is it important to treat dementia-related psychosis?
It is important to treat DRP because evidences shows that people who have these symptoms progress more rapidly and have a worse prognosis. At this point, it remains unclear if treating these symptoms directly correlates to improved prognoses. However, effective treatment is still imperative because these symptoms have many other negative consequences. For example, high levels of distress, caregiver/care partner burden, aggressive and violent behaviours, visits to the emergency department, or admittance to long-term care homes.
How is dementia-related psychosis treated?
The mainstay of treatment for DRP are antipsychotic medications. A variety of these medications exist, and they are taken orally. They are modestly effective; in the right person, they can be quite helpful – it really depends on which symptoms someone is experiencing. For example, antipsychotics work better for persecutory delusions, and not as well for visual hallucinations or misidentification delusions. Unfortunately, in a percentage of people living with dementia, antipsychotic medications can accelerate mortality. Scientists are not completely sure why, but it could be related to an increase in vascular events in the brain (e.g., damaged blood vessels, restricted blood flow).
There are other social and behavioural interventions that can be effective. The approach to interacting with someone experiencing DRP is important. Arguments about a delusion or hallucination should be avoided; instead, their concerns should be validated, and the focus of discussion should be shifted. It is also important to pay attention to someone’s level of stimulation, as over stimulation (e.g., too much noise, stress, disruption in someone’s day) can be problematic. Correcting underlying sensory deficits (i.e., making sure someone can see and hear properly) is also important as people can experience psychotic symptoms when they misconstrue things in their environment. Lastly, any underlying medical conditions should be optimized.
What’s happening in research? Next steps?
Some existing drug therapies, for example SSRI (selective serotonin reuptake inhibitors) medications, are being studied for their potential to manage DRP. There are also new drug treatments being developed specifically for DRP. Importantly, revised clinical criteria and research criteria have been developed for DRP, which will improve diagnosis and treatment of symptoms. Finally, identifying underlying brain mechanisms and the extent to which they are related to brain pathology will be key.
