A proposal for a semantic change in the current diagnostic criteria of Parkinson’s disease Psychosis

Psychosis may emerge as part of Parkinson’s disease (PD) process but is also associated with PD treatment. When the NINDS-NIMH criteria were applied to a cross-sectional PD cohort, the prevalence of PD psychosis in PD patients reached 60% [1].The most frequent symptoms in PD-associated psychosis (PDAP) are related to sensory perception areas, especially hallucinations. Graham et al. [2], reported that 70% of their patients with hallucinations had retained insight. This seems a contradiction because psychosis is a mental disorder characterized by symptoms, such as delusions or hallucinations that indicate an impaired contact with reality [3]. If we adhere to this definition, which is in fact the common and accepted one, those patients who retained insight about abnormal sensory perceptive phenomena should not be diagnosed as “psychotic”. Moreover, Fénelon and Alves reviewed the epidemiology of psychosis across different centers worldwide, showing that although psychosis could be diagnosed at that point of time, visual hallucinations were not always present for diagnosis: other features were taken into account to make this diagnosis for example the presence of delusions or illusions [4].