The Link Between Apathy and Parkinson's
Apathy is an often-distressing non-motor symptom that affects many people with Parkinson’s disease (PD). The definition of what apathy means in the context of Parkinson’s has changed substantially over the years, but is now defined as a profound reduction of feeling, interest, and motivation that is not a result of cognitive impairment, reduced consciousness, or emotional upset. Due to the limited number of studies on this topic, estimates of the prevalence of apathy range from 12% to 70% of people with Parkinson’s. To this day, there also exist few standardized assessment tools to measure apathy. What is known, however, is that it poses a significant challenge to people with Parkinson’s and their loved ones. Experiencing apathy can result in a significant decrease in quality of life and increase in caregiver burden (Foley & Cipolotti, 2021).
There is growing evidence that like anxiety, apathy in Parkinson’s is not just a response to living with a chronic health condition, but may instead originate from disruption in brain pathways, as well as decreased levels of dopamine. It is also not the same thing as depression, even though there is some overlap between their respective symptoms, with studies showing that apathy can be a separate condition from depression in people with Parkinson’s. However, apathy is strongly correlated with several factors, such as also experiencing depression, anxiety, and fatigue (Ineichen & Baumann-Vogel, 2021).
One small study followed two groups (one group experiencing apathy, another not) of people with Parkinson’s disease for 18 months. At the time of the first assessment, both groups were receiving PD medications that were optimally dosed for each individual, yet there were clear differences in the levels of apathy between the two groups. As a result, the study authors suggested it is not possible for dopamine levels to completely explain rates of apathy amongst people with Parkinson’s. However, they acknowledged feedback from a fellow researcher that argued the ‘optimal’ dose of anti-parkinsonian medication is usually based only on control of motor symptoms, not non-motor ones like apathy. Because dopaminergic medications affect both motor and non-motor parts of the brain, it is possible the dose that is best for motor symptoms may not be ideal for controlling non-motor ones (Dujardin et al., 2009).
Additionally, apathy is linked to a higher risk of developing dementia as the disease progresses. The study mentioned above proposed the idea that the loss of basal forebrain cholinergic neurons (BFCNs) as a result of Parkinson’s disease is a major cause of cognitive decline and dementia, as well as neuropsychiatric symptoms like apathy. BFCNs are a special type of nerve cell in the brain that play an important role in cognition, as well as attention and memory (Martinez et al., 2021). In the study, the group of people with apathy showed lower cognitive function scores after 18 months than the non-apathetic group, suggesting that apathy may be predictive of dementia over time (Dujardin et al., 2009).
In addition to the associations with dementia, apathy also can have a negative impact on carepartners, sometimes even impacting them more than the person with Parkinson’s. In fact, some studies have shown that carepartners report apathy to be the single most troublesome symptom in people with PD (Foley & Cipolotti, 2021). If a carepartner does not understand the origins of apathy, they may see their loved one as lazy, difficult, and hard to motivate. As a result, the carepartner may experience burnout, and the relationship may suffer. This is why it is imperative that family and friends see apathy as a symptom of the illness itself, not as a personal failing. Adjusting expectations can go a long way. No one would ever tell a person with Parkinson’s to “just stop their tremor or freezing.” Similarly, this compassion must be extended to non-motor symptoms like apathy (Kluger, 2017).
If you or your loved one are struggling with apathy, make sure to discuss your concerns with your healthcare team. There may be possible medication changes or additions that can help. Don’t be discouraged if it takes several trials to find the right dose or type of medication for you. It is also important to make sure any healthcare practitioner prescribing medication specifically to treat apathy is familiar with Parkinson’s disease. Sometimes people with PD are given antidepressant medications for apathy by their psychiatrist, but these may not always be effective at treating the condition and, in some cases, can actually make it worse (Kluger, 2017).
It also may not come as a surprise that, like many Parkinson’s symptoms, apathy seems to be reduced by regular physical activity. In 2021, a study found that people with early-stage Parkinson’s disease that were more active were less apathetic. The researchers of that study also suggested that exercise can act as a motivating force by encouraging self-help behaviours, resulting in an overall improvement in other Parkinson’s symptoms (Ng et al., 2021). Another academic review of non-pharmacological interventions for treating apathy in PD found that a Nordic walking program, which uses walking poles to engage the upper body, was especially effective. It seems the full-body involvement increased participants’ sense of safety while exercising, which gave them a boost in feelings of autonomy (Mele et al., 2021). Regardless of what exercise program you choose, the most important part is that it is something you find empowering and enjoyable.
Sources
Dujardin, K., Sockeel, P., Delliaux, M., Destée, A., & Defebvre, L. (2009). Apathy may herald cognitive decline and dementia in Parkinson's disease. Movement Disorders, 24(16), 2391-2397. https://doi.org/10.1002/mds.22843
Foley, J. A. & Cipolotti, L. (2021). Apathy in Parkinson’s disease: A retrospective study of its prevalence and relationship with mood, anxiety, and cognitive function. Frontiers in Psychology, 22. https://doi.org/10.3389/fpsyg.2021.749624
Ineichen, C. & Baumann-Vogel, H. (2021). Deconstructing apathy in Parkinson's disease: challenges in isolating core components of apathy from depression, anxiety, and fatigue. Frontiers in Neurology, 12. https://doi.org/10.3389/fneur.2021.720921
Kluger, B. (2017). Provincial Conference 2017: Apathy & Non-Motor Symptoms with Dr. Benzi Kluger. [Video file]. YouTube. https://bit.ly/apathydrkluger
Martinez, J. L., Zammit, M. D., West, N. R., Christian, B. T., & Bhattacharyya, A. (2021). Basal forebrain cholinergic neurons: Linking down syndrome and Alzheimer's disease. Frontiers in Aging Neuroscience. https://doi.org/10.3389/fnagi.2021.703876
Mele, B., Ismail, Z., Goodarzi, Z., Pringsheim, T., Lew, G., & Holroyd–Leduc, J. (2021). Non-pharmacologic interventions to treat apathy in Parkinson’s disease: A realist review. Clinical Parkinsonism & Related Disorders, 4. https://doi.org/10.1016/j.prdoa.2021.100096
Ng, S. Y., Chia, N. S., Abbas, M. M, Saffari, E. S., Choi, X., Heng, D. L., Xu, Z., Tay, K., Au, W., Tan, E., & Tan L. C. (2021). Physical activity improves anxiety and apathy in early Parkinson's disease: A longitudinal follow-up study. Frontiers in Neurology, 11. https://doi.org/10.3389/fneur.2020.625897
This content was published in the Spring 2023 edition of our quarterly magazine, Viewpoints. The content was accurate as of this publication date.