Neuropsychiatric symptoms in Parkinson's disease: aetiology, diagnosis and treatment

Historically, Parkinson’s disease (PD) was viewed as a motor disorder and it is only in recent years that the spectrum of non-motor disorders associated with the condition has been fully
recognized. There is a broad scope of neuropsychiatric manifestations, including depression, anxiety, apathy, psychosis and cognitive impairment. Patients are more predisposed to
delirium and PD treatments give rise to specific syndromes including impulse control disorders, dopamine agonist withdrawal syndrome and dopamine dysregulation syndrome. This article seeks to give a broad overview of the spectrum of these conditions, describe the association with PD disease severity and degree to which dopaminergic degeneration and / or treatment influences symptoms. We highlight useful assessment scales that inform diagnosis and the current treatment strategies can be employed to ameliorate these troublesome symptoms that frequently negatively affect quality of life for people with PD.