Capgras Syndrome in Lewy Body Dementias (LBD) Associated with Anxiety and Hallucinations


Among people with Lewy body dementias, delusions, or false beliefs, are common. One of these delusions is a belief that a familiar person or place has been replaced with an identical imposter. This type of delusion is called Capgras syndrome, and it affects about 17 percent of people with dementia with Lewy bodies (DLB). It is also a common delusion experienced by people with Parkinson’s disease dementia, which is also under the LBD umbrella.

First, let’s talk a little bit more about what Capgras syndrome entails. Also known as imposter syndrome, Capgras syndrome (CS) is a psychiatric disorder. People with CS may believe that a loved one, like a friend, family member, or spouse, has been replaced with a duplicate. This can lead to a strained relationship between the caregiver and person with LBD. Interestingly, the strongest emotional reaction for people with CS happens when seeing the faces of people they love, and phone conversations don’t provoke the same response. Therefore, it’s believed that CS has a strong visual component.

According to Dr. James E. Galvin, the designer and senior author of one study about DLB and Capgras syndrome, “Early diagnosis of DLB and Capgras syndrome may allow for early pharmacological intervention and an opportunity to reduce caregiver burden and depression.”

The conservative use of certain treatments may be helpful with Capgras syndrome, such as medications like pimavanserin, quetiapine and clozapine.  These are newer ‘atypical’ antipsychotic medications. The most common treatment for cognitive symptoms in LBD is the class of medications called cholinesterase inhibitors, which may also help with some of the psychiatric symptoms in LBD. These are medicines that block the breakdown of a neurotransmitter called acetylcholine. People with LBD have reduced acetylcholine levels in the brain, so cholinesterase inhibitors can help with dementia symptoms like cognitive changes.

Decreasing certain medications may also be warranted. For people with LBD who are receiving treatment for parkinsonism (problems with physical movement), medications that replace dopamine may need to be decreased. These medications are known to sometimes worsen behavioral symptoms. It is important to discuss your symptoms and treatment options with your attending physician to ensure the best plan for you.

The Lewy Body Dementia Association is a nonprofit organization dedicated to raising awareness of LBD, with a focus on serving all individuals affected by this disease. We work to support people with LBD, along with their families and care partners, through outreach, education, and research. To learn more, contact us through our website, sign up for our email newsletter, or connect with us on Facebook or Twitter.

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