Opicapone Treatment Initiation Open-Label Study

Inclusion Criteria: * Must be able to complete electronic patient-reported outcome instruments * Parkinson's disease patients experiencing "off" episodes * Patient receiving concomitant levodopa/carbidopa, and as deemed appropriate by the physician, newly initiating ONGENTYS as adjunctive treatment Exclusion Criteria: * Patient is not cognitively able to complete the study requirements * Patient is not able to complete the study duration of 6 months * History of moderate or severe hepatic impairment * Patient has end-stage renal disease * Concomitant use of non-selective monoamine oxidase (MAO) inhibitor or catechol-O-methyltransferase (COMT) inhibitors (patients entering study may switch from other COMT inhibitors to ONGENTYS) * History of pheochromocytoma, paraganglioma, or other catecholamine-secreting neoplasms * Currently enrolled in an interventional clinical trial * Currently or previously received ONGENTYS