Dopaminergic Therapy in Parkinson's Disease: Psychiatric Symptoms, Cognition, and Everyday Functioning

Parkinson's disease (PD) patients commonly suffer from psychiatric symptoms, as well as mild cognitive deficits even in the absence of global cognitive dysfunction. Examination of psychiatric and cognitive deficits in PD is important for predicting the course of decline and disease progression, as the presence of these deficits and potential conversion to more serious psychiatric illness and/or Parkinson's disease with dementia has a significant impact on everyday functioning and quality of life. Deficits in everyday functioning limit PD patients' independence and increases dependence on caregivers. Taken together, impairments in motor, psychiatric and cognitive functioning indicates that PD patients are at an increased risk for decline in everyday functioning and decreased quality of life.;Dopaminergic therapy is the primary medication therapy utilized in PD. Dopaminergic medications such as levodopa therapy and dopamine agonists were developed for treatment of motor symptoms, and research has shown it also affects psychiatric and cognitive functioning. Whether the impact of dopaminergic therapy on improvement in psychiatric symptoms and cognition extends to everyday functioning has not been investigated. The neurophysiology of PD indicates that dopaminergic drugs have effects not only on motor systems, but psychiatric and cognitive functioning as well, all of which may impact the ability to perform everyday activities. Dopamine projects throughout the cortex and is highly important in maintenance of nigrostriatal, mesolimbic, and mesocortical pathway functions, contributing to motor, psychiatric, and cognitive functioning, respectively.;Further understanding of the role of dopamine and effects of dopaminergic therapy on psychiatric symptoms, cognition, and everyday functioning is necessary to improve the power to predict future decline, and improve treatment planning to address differential symptoms experienced in PD. Investigating these factors has implications for potentially increased functional independence and quality of life. Patterns of improvement in psychiatric and cognitive symptoms through dopaminergic therapy may differentially impact potential gains in everyday functioning abilities. A neuroscientific approach will be utilized to examine the most common medication treatment in PD, its effect on measures of everyday functioning, and psychiatric and cognitive symptoms that may impact everyday functioning.