(77) Incidence of Antipsychotic Use Among Community Dwellers With and Without Parkinson's Disease

Publication Number: 408

Background: Persons with Parkinson disease can have symptoms like hallucinations and delusions even before diagnosis. Previous studies have assessed antipsychotic use after the PD diagnosis, but the incidence of antipsychotic use before PD diagnosis is not known.

Objectives: To study the incidence of antipsychotic use among community-dwelling persons with and without PD from 10 years before to 10 years after the diagnosis of PD.

Methods: The study was based on the nationwide register-based Finnish Study on Parkinson’s disease (FINPARK). Altogether 20,994 community-dwelling persons with PD who received PD diagnosis in 1996-2015 and 142,944 matched comparison persons who had not used antipsychotics during one-year washout before the follow-up were included. Antipsychotic use in six-month time windows was assessed from the Prescription register.

Results: During the entire follow-up 26.9 % (n=5,654) of people with PD initiated antipsychotics in comparison to 9.7 % (n=13,887) of people without PD. Initiation of antipsychotic drug use was more common in people with PD throughout the whole study, but the incidence rate increased steeply in people with PD approximately four years before the diagnosis of PD. The most commonly initiated antipsychotic among people with PD was quetiapine (n= 3,642, 64.1%), followed by risperidone (n= 856, 15.5%). Among people without PD risperidone was the most initiated antipsychotic (n=5,232, 37.2%), followed by quetiapine (n=4,331, 30.8%).

Conclusions: The incidence of antipsychotic use starts to emerge before the diagnosis of PD. These results illustrate that the neuropsychiatric symptoms of PD can begin years before the PD diagnosis.