Psychosis in Alzheimer's Disease

Health Professional

Psychosis is common in Alzheimer's disease and affects between about 40 percent and 50 percent of people over the course of the disease. It causes significant distress to the patient and to families and caregivers. Psychosis itself does not describe a disease so much as an abnormal condition of the mind where people find it difficult to tell what is real and what - in its simplest terms - is imagination.

In a neurodegenerative disease such as Alzheimer's disease (AD) where confusion is also a central symptom, it can be difficult for caregivers to understand the difference between confusion and psychosis as both states can sometimes result in the same type of behaviors. People experiencing confusion or psychosis can, for instance, be suspicious, uncooperative, sometimes combative, argumentative or fearful. But there are some definitive differences.

Confusion is defined as impaired orientation with respect to time, place, or person. It is not difficult to imagine how our behavior would change if we became confused. We could easily become fearful if we did not recognize our surroundings or family members or nursing staff. We might become uncooperative or shout out if we were frightened. Although someone with Alzheimer's experiencing confusion may show these symptoms, the patient would not be considered to be suffering from psychosis.

In psychosis there are a number of specific symptoms that include hallucinations, delusions and paranoia. The hallucinations can affect any of the five senses but most commonly affect auditory and/or visual senses. We would not find these symptoms in someone with Alzheimer's who was confused. Equally, they would not be considered to be deluded if they were confused. Delusions are defined as a fixed and false belief that, even in the face of evidence to the contary, will not change.

Paranoia is one symptom that can be very similar in both confusion and psychosis. What differs is the depth of belief. So if we consider paranoia as an unfounded or exaggerated distrust of others, or someone who constantly suspects the motives of those around them, or that some or all people are "out to get them" it may be seen as a symptom of either. What differs is whether the belief is fixed and unshakable.

The occurrence of psychotic symptoms in people with Alzheimer's has been found in some studies to be familial. It has an estimated heritability of 61 percent. One of the most consistent findings in studies has been that Alzheimer's and psychosis is in those with greater cognitive impairment. Cognition is perceiving, recognizing, conceiving, judging, reasoning, and imagining.

Diagnosing psychosis is complex and treatment requires medical intervention. The doctor, psychiatrist, or gerontologist will analyse the patient's behavior, their thought content through conversations and interactions with others in their environment. Caregiver information will be important in forming his/her diagnosis. The doctor will also consider whether the psychosis has been caused by other diseases and conditions, by side effects or by drug interactions, as well as from the patient's medical and social history.

More on Psychosis in Alzheimer's disease:

Caregivers Guide to Drugs used for Agitation and Psychosis

Some Antipsychotic Medical Significantly Increases the Incidence of Death in Nursing Home Residents

Confusion-When should Caregivers Seek Help?

Sharepose Sources include:

DeMichele-Sweet, M.A.A et al. 2011. Psychosis in Alzheimer's Disease in the National Alzheimer's Disease Coordinating Center Uniform Data Set:Clinical Correlates and Association with Apolipoprotein. International Journal of Alzheimer's Disease.