Eligibility Criteria:
Inclusion Criteria:
* Formal diagnosis of Parkinson Disease
Exclusion Criteria:
* Confirmation that the individual carries a GBA variant (GBA positive). These individuals will be referred to sister-study, RAPSODI.
* History of Parkinsonism (progressive supranuclear palsy, multiple system atrophy, traumatic, manganese toxicity, postencephalitic, vascular PD; drug induced PD; corticobasal degeneration)
* Individuals with another neurological disorder including: dementia, movement disorders, and motor neurone disease.
* Individuals on drugs known to be associated with parkinsonism, including neuroleptic agents (Amisulpride, Chlorpromazine Hydrochloride, Flupenthixol, Fluphenazine Hydrochloride, Haloperidol, Methotrimeprazine, Levomepromazine, Olanzapine, Oxypertine, Pericyazine, Perphenazine, Pimozide, Pipotiazine, Prochlorperazine, Promazine Hydrochloride, Reserpine, Risperidone, Sulpiride, Thioridazine, Trifluoperazine, Zuclopenthixol acetate, Zotepine), plus Bupropion, , Lithium, Methyldopa, Metoclopramide and Sodium Valproate).