Stress and Mindfulness in Parkinson's Disease: Clinical Effects and Potential Underlying Mechanisms

Abstract

Patients with Parkinson's disease (PD) are very vulnerable to the negative effects of psychological distress: neuropsychiatric symptoms, such as anxiety and depression, are highly prevalent in PD; motor symptoms (such as tremor) typically worsen in stressful situations; and dopaminergic medication is less effective. Furthermore, animal studies of PD suggest that chronic stress may accelerate disease progression. Adequate self-management strategies are therefore essential to reduce the detrimental effects of chronic stress on PD. Mindfulness-based interventions encourage individuals to independently self-manage and adapt to the challenges created by their condition. In PD, emerging clinical evidence suggests that mindfulness-based interventions may reduce psychological distress and improve clinical symptoms, but insight into the underlying mechanisms is lacking. In this viewpoint, we provide a systematic overview of existing mindfulness trials in PD. Furthermore, we discuss the cerebral mechanisms involved in acute and chronic stress, and the impact of mindfulness-based interventions on these networks. In addition, we delineate a hypothetical mechanistic framework of how chronic stress may increase the susceptibility for neuropsychiatric symptoms in PD and may potentially even influence disease progression. We end with offering recommendations for future research. © 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Keywords: Parkinson's disease; anxiety; depression; mindfulness; psychological stress; quality of life.

© 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Figures

FIG. 1

Brain network activity related to stress and mindfulness. (A) Brain regions are activated (blue) or deactivated (orange) during acute stress, 28 resulting in neuroplastic structural changes in core regions after chronic stress. 29 (B) Brain regions for which altered activation, 30 as well as structural brain changes, 31 have repeatedly been demonstrated in mindfulness practitioners. Blue regions consistently show activation during mindfulness‐related tasks or resting state, whereas orange regions were found to be deactivated. [Color figure can be viewed at wileyonlinelibrary.com]

FIG. 2

A pathophysiological model of chronic stress in Parkinson's disease (PD). This figure provides a hypothetical (and simplified) framework of how chronic stress in patients with PD may lead to higher susceptibility for depressive and anxiety disorders on the one hand, and to a more rapid progression of the disease on the other hand. Upper part: the high levels of glucocorticoids that result from chronic stress decrease the expression of brain‐derived neurotrophic factor (BDNF), which induces atrophy in the hippocampus and prefrontal cortex and growth in the amygdala. 33 This increases the risk for development of depressive and anxiety disorders. 34 Hippocampal atrophy also disinhibits the hypothalamic–pituitary–adrenal (HPA) axis, further increasing glucocorticoid levels. 35 Lower part: elevated glucocorticoid levels also increase neuroinflammation 36 and production of reactive oxygen species (ROS). 37 These molecular changes may contribute to degeneration of nigrostriatal dopaminergic neurons. 38