Apathy in Parkinson's disease (PD) is a significant public health problem with serious adverse consequences for patients and caregivers. Apathy is present in up to 70% of people with PD. Patients suffering from apathy experience decreased motivation, relying heavily on caregivers to initiate daily activities. The presence of apathy is associated with worse quality of life for patients and caregivers. Moreover, patients with apathy have a faster disease progression and increased likelihood of development of cognitive impairment.~Despite the high prevalence of apathy in PD and its serious consequences, there are no proven treatments for this condition. Dopaminergic enhancement appears as a potential mechanism as there is evidence that degeneration of the frontostriatal circuits involving the prefrontal cortex is one of the main mechanisms for the presence of apathy in PD as well as other neurodegenerative disorders, such as Alzheimer's disease (AD). This degeneration is associated with deficits in dopaminergic and noradrenergic input fibers to the prefrontal cortex.~Methylphenidate, a dopamine and noradrenaline reuptake inhibitor, has been shown to be safe and effective in PD in the treatment of motor and cognitive symptoms, and several small trials and case series reported improvement in motivation and mood. Recently, methylphenidate was shown to be safe and improve apathy in AD in a series of well-controlled studies conducted by members of our team. This represents a relevant result as similar pathophysiology for apathy has been suggested in both AD and PD.~Given the common biological pathways in the onset of apathy in both disorders, we propose that, as is the case in AD, methylphenidate will be a safe and effective treatment for apathy in PD.~The goal of the proposed study of Methylphenidate for Apathy in Veterans with Parkinson's Disease (MAV-PD) is to expand upon this encouraging preliminary work by evaluating methylphenidate for the treatment of apathy in PD Veteran patients. It is our strong belief that a trial designed specifically in Veteran population should be conducted, as reliance on data from civilian populations who differ in their level of medical and psychiatric comorbidity, which influence drug response, may not be applicable to Veterans with PD.~This study will employ a single-site, parallel, randomized, double-blind, placebo-controlled design conducted on 60 Veterans with apathy and PD. MAV-PD is designed specifically for PD patients with apathy, and as such it employs a concise battery of neuropsychological tests that have been chosen for this patient group.~This project is of great importance because it will explore the efficacy and safety of a promising dopamine agonist for treating apathy in PD, where there are no proven treatment options. Should methylphenidate be found effective, it will likely become the first-line therapy for apathy in PD.
Apathy is one of the most common behavioral symptoms of Parkinson's disease. Patients with apathy show diminution in motivation and goal-directed behaviors, which is a fundamental aspect of human functioning, affecting dependency and quality of life. Although apathy is thought to be potentially treatable currently there are no effective treatments for apathy. Given the higher incidence of medical and psychiatric comorbidities, the Veterans Affairs health system represents a unique population for which medication response may be different from the general population. This study aims to evaluate if a medication that has already been proven to be useful in Alzheimer's disease patients with apathy, could be helpful in Parkinson's disease as well as decreasing its debilitating consequences and reducing patients' dependency on caregivers, providing well-deserved relief to patients and their loved ones.