Psychosis associated with Parkinson Disease (PD) can be diagnosed if certain criteria are present.


Criteria for the diagnosis of psychosis in a patient with PD:

(1) presence of Parkinson's disease

(2) presence of 2 or more characteristic symptoms of psychosis (see below)

(3) The onset of Parkinson's Disease precedes the onset of the psychotic symptoms.

(4) The psychotic symptoms persist for over 1 month (may be either recurrent or continuous)

(5) The psychotic symptoms cannot be explained by another diagnosis (see below).


Psychotic symptoms include:

(1) false sense of presence (belief that someone is present when no one is)

(2) delusions

(3) illusions

(4) hallucinations


Conditions to exclude:

(1) general medical condition causing delirium

(2) dementia with Lewy bodies

(3) schizophrenia or schizoaffective disorder

(4) delusional disorder

(5) mood disorder with psychotic features


Additional conditions to note:

(1) presence or absence of insight

(2) presence or absence of dementia

(3) any therapy for Parkinson's disease


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