Mental manifestations in Parkinson's disease

Parkinson's is usually considered as a motor disorder but many non motor symptoms make it a more complex disease. The mental manifestations of PD, particularly depression, psychosis, cognitive impairment/dementia are among the main non motor symptoms which characterize PD and contribute to its disability. Depression and anxiety can occur before the first motor symptoms, predate the diagnosis of PD but they come many years before PD during the pre-motor phase of PD. Cognitive impairment in PD patient involve attention, psychomotor speed, verbal memory, and visuospatial and executive functions, and these characteristics make it different from Alzheimer Disease. A minority of PD patients develops compulsive behaviors while receiving dopainine-replacement therapy, induding pathological garnbling compulsive shopping, and punding Their effect on patients and caregivers may be even more disabling than motor symptoms. This review describes the various mental disturbances in relation to the phases of PD, including the presymptomatic period and the phase of symptomatic disease, before and after the drug treatment, and after the surgical procedure of deep brain stimulation (DBS). It also offers some notes on useful screening scoring measures and treatment of mental manifestations of PD.