Decision-Making Process in Parkinson’s Disease: A Systematic Review

Parkinson's disease (PD) is a common neurodegenerative disorder affecting 2-3% of the elderly population, and it is characterized by a loss of dopamine-producing neurons in the substantia nigra. The mainly described symptoms affect the motor system, but there is increasing awareness of non-motor symptoms, such as addictions and decision-making (DM) impairment. DM is a fundamental function to daily activities that allows us to select choose an option when faced with multiple alternatives. Age-related decline in executive functioning has been associated with riskier decision-making style. The aim of this work is to examine studies that analyze decision-making processes under uncertainty condition in subjects with Parkinson's disease and healthy older people. The systematic review was conducted according to the PRISMA Statement 2020. Thirty-three studies were identified. The results highlighted that decision-making in ambiguous and risky situations is impaired in individuals with Parkinson's disease compared to the healthy population. Clinical subjects have a higher propensity to take risks, more disadvantageous choices, poorer performance, and a lower ability to learn adequate strategies. Accordingly, the non-motor symptom involving DM as high cognitive functions influencing daily activities should be considered in the clinical assessment of PD.