Dopamine interactions play a critical role
Dopamine interactions in the limbic system are involved in stress and depression. In Parkinson’s disease, the pessimism measured using a harm-avoidance personality score related to dopamine uptake in the right caudate nucleus, or one of the structures that make up the dorsal striatum or a portion of the brain that is associated with motor processes and a part of the brain’s reward system. It has been found by these studies that mood fluctuations occur independently from motor fluctuations. The implications state that involvement of the ventricle rather than dorsal brain circuitry can be improved with antiparkinsonian medication.
Take these studies a bit further, and conclusions state that the loss of noradrenaline and dopamine in the amygdala plays a role in generating symptoms in Parkinson’s patients. The amygdala performs a primary role in the processing of memory, emotional responses and decision-making in the brain. Dopamine and noradrenaline reductions, it can be concluded, are the reasons that Parkinson’s patients have a loss of memory, have varied emotional responses and are not good at making decisions once the disease has taken hold.