In 1817, the first description of Parkinson’s disease (PD) was detailed in the essay ‘The shaking palsy’ authored by James Parkinson. Even then, over 200 years ago, it was identified as a disorder with multiple physical and psychological symptoms – motor, cognitive, and emotional manifestations.

Like other neurodegenerative diseases, PD occurs when nerve cells in the brain or peripheral nervous system lose function over time and ultimately cease to operate. In PD, this cell impairment and death leads to a reduction in the production of the chemical dopamine; this neurotransmitter plays several critical roles in cells, such as regulating the body's movements and in a person’s emotional responses.

Undoubtedly, it is this combination of gradual motor, emotional, and cognitive impairment that causes the profound and insidious decline in mental wellness for those living with the condition. In 2017, Parkinson's UK surveyed people affected by PD across the UK. A total of 745 people responded to the survey sharing their experiences of how mental health challenges had influenced their life and mobility-related symptoms, as well as detailing the support they have received. The survey revealed that 70% of respondents felt that their mental health had significantly impacted their overall quality of life.

Further findings broke down this impact:

  • Over 70% of respondents stated that their mental health had affected their ability to socialise.
  • Nearly 50% reported finding it more challenging to leave the house due to their mindset.
  • Over 50% believed their mental health has negatively impacted their close relationships.
  • 27% reported suicidal ideation.
  • Nearly 30% reported they had stopped exercising.

Although despite the apparent association between mental health and PD (similar to various other neurodegenerative conditions), many people find it difficult to access services and receive effective psychological treatment.

High demand and referral hurdles for specialist psychological support

A 2020 report conducted by the Neurological Alliance showed that many people with neurological conditions struggle to access adequate mental healthcare that meets the complex needs of their condition. Likewise, previous patient surveys from 2019 showed that 58% of people with a neurological condition had not been asked about their mental health by clinicians, and 40% of patients with a neurological condition felt that their mental health needs were not being met.

In terms of PD, it is routine for people to wait months, and in some cases years, before seeing a specialist mental health professional, after a problem has been first identified. Analysis from the Neurological Alliance and the Royal College of Psychiatry’s Faculty of Neuropsychiatry has found that waiting times across the UK are excessively lengthy:

  • Waiting times for King’s College’s SLaM neuropsychiatric services range from a two year wait (96 weeks) for inpatient and nearly a year (50 weeks) for outpatient.
  • University College London Hospital waiting times average at 64 weeks wait for inpatient and 16 weeks for outpatient.
  • North Bristol NHS Trust – 6 weeks for inpatient and 50 for outpatient.
  • Manchester Centre for Clinical Neurosciences – 8 weeks for inpatient and 39 for outpatient.

Organisations advocating for people with neurological conditions have said that these waiting times coupled with an increasing need for services are especially concerning considering the high demand prior to the Covid-19 pandemic. In an interview with Mental Health Today, Georgina Carr, Chief Executive of the Neurological Alliance, described the state of access to services over the last two years, she said:

"People found it really very difficult to get the treatments they need, including the mental health support. People have experienced treatment delays and cancellations, as well as loss, loneliness, isolation, and the other various impacts of the pandemic. We have looked at waiting times in England, and it has reached 168,000 people waiting for neurology appointments – that is, people waiting for answers – specialist input to understand what is happening in their body and mind.”

Understanding the interplay and intertwining of co-occurring mental health and neurodegenerative conditions

In 2018, the All-Party Parliamentary Group (APPG) on Parkinson’s released the findings of an inquiry. The published report established that motor neurodegenerative diseases are frequently complicated by co-occurring psychiatric problems in terms of quality of life and treatment. Yet, the APPG concluded that these psychiatric comorbidities are often neither recognised as a co-occurring condition nor adequately treated.

One of the primary causes of this gap in standards of care, which the inquiry identified, was the widespread lack of knowledge amongst mental health professionals about PD, producing a patchy and disjointed landscape of treatment provision, ultimately not meeting the specific needs of many people with the condition.

Psychiatric illnesses and neurodegenerative diseases have been shown a bi-directional relationship. Research indicates that those with a neurodegenerative disease are more likely to develop a mental health condition than the general population, and people with significant mental health conditions (such as stress-related psychiatric conditions) are more likely to develop a neurodegenerative disease later in life. It has been suggested that this is due to the conditions having similar physiological pathologies; depression, schizophrenia, and anxiety, as well as neurodegenerative disorders, have been linked to imbalances in neurotransmitters and hormones, such as low levels of serotonin and dopamine, as well as to cardiovascular diseases, for instance, coronary heart disease and hypertension.

In our interview, Ms Carr described the intimate connection between the physiological and mental health symptoms, which is characteristic of neurological conditions. She, in many ways, further illustrated what seems to be an evidently artificial and superficial distinction, which because of a siloed system of physical and mental healthcare is unhelpful for people with neurological conditions in accessing the specialist support they require. Ms Carr said:

"It is really complex. You cannot divorce physical and mental health. If someone is living with a neurological condition, there are lots of different ways in which those two things might come into play. For example, a neurological condition may trigger a whole range of mental health issues, such as anxiety and depression. As you come to try to come to terms with your condition, you may also struggle to get the support you need to come in to manage that condition, then changes in your brain function may well have an impact on your cognition, mood, and emotions.”

Another way that clinicians and people with neurodegenerative illnesses find it difficult to identify these comorbidities, as a result of the bi-directional relationship between neurodegenerative and mental health conditions, is that they often have overlapping features.

In 2018, an expert on neurodegenerative diseases, Professor Susan Marie Maixner, said at the Parkinson’s Disease and You Symposium that these overlapping symptoms have the potential to lead to misdiagnosis. For example, in terms of PD, she explained that motor symptoms such as stooped posture and slow movement or behavioural changes could be viewed solely through the physical prognosis of the condition rather than as a sign of a depressed emotional state. On the other hand, further complicating this diagnostic conundrum, research suggests that psychiatric symptoms, such as depression and anxiety, may be a prodromal phase in the later development of PD and may be even present up to 20 years before the onset of motor signs typically associated with the condition. Therefore, mental ill-health may, in fact, be an early indicator or be an overlapping feature of a developing neurological condition.

Writing for Mental Health Today, Ms C provided us with her lived experience of PD and the role that a diagnosis has had on her mental health.

Lived experience: Ms C’s story

I was diagnosed with Parkinson's Disease in October 2008 at the age of 48. Nothing prepares you for news like this, especially if, like me, you were not expecting it. My appointment with the temporary neurologist was at 10.00. By 10.30, I was in my car with a prescription, some information leaflets, and the knowledge that I would be sent an appointment with a specialist nurse. Since then, my care has been managed by a variety of specialist nurses; I have not seen a specialist. These specialist nurses do a great job at adjusting medication and monitoring the progress of the disease, but their time is too limited to provide emotional support.

Coping with such a devastating piece of news is a very personal response; I went into denial. I did not tell anyone except my family and tried to mask the symptoms, especially at work. One of my main symptoms was losing the ability to write clearly, a real problem for a primary school teacher. It took a few years before I could trust myself with telling people. A significant reason for this is the public view of PD sufferers as old people sitting in the corner shaking and dribbling. This can be reinforced by the medical profession; when I eventually asked for details of support groups, I was told to avoid them as they would scare me. I still can't bring myself to contact the local branch of PDS. It has taken me 13 years to apply for a blue badge, as in my eyes, it meant accepting that I was disabled.

The low point of the last 13 years was accepting that I was no longer fit to teach. This goes deeper than the loss of a job; it is an attack on who you are. Suddenly the thing that proves your worth to society has gone, and it is hard to replace. It was suggested that there was plenty to keep me busy, but few people realise how physically and mentally tiring the various neurological diseases are or how erratic symptoms can be. What can be possible one day might be unachievable the next. Simple ways of keeping busy are not so simple when motor skills are impaired. I had to give up driving which further restricted my choice of activities.

The recent restrictions on us caused by Covid-19 have not helped in maintaining a positive state of mind.

However, over the past 13 years, I have carefully constructed a support network of family and friends and learnt that it is ok to ask for help. People are willing to provide transport and make their own coffee when they come to visit, and strangers will help when you are out; so, it is important to accept help without feeling resentful, and when one can do this, it is a big step forward in coming to terms with the disease.

What can be done to improve accessibility and treatment for people with PD?

From the discussion above it appears evident that we can separate the numerous complex issues surrounding mental health and PD into three broad categories, the systemic, the contextual, and the symptomatic. The systemic, centring around issues with gaining a diagnosis and the referral hurdles experienced in receiving specialist support. The contextual, being the distress associated with declining accessibility of activities, linked to quality of life indicators, such as employment or feeling able to engage with the outside world. And the symptomatic related with the prognosis of the condition, and the resultant psychiatric illnesses, which become apparent due to physiological changes (diminishing dopamine levels and ever more impactful motor symptoms).

The majority of the systemic issues are concerned with gaining proper treatment and are on the face of it are part of a much larger seemingly unending sore in healthcare – the need for more funding and greater integration of services – which will only be solvable through the actions of policymakers. On the other hand, as literature on the topic suggests, mental health professionals can play a vital role in alleviating some of the contextual and symptomatic challenges connected to PD.

Researchers at Minds & Movement, an initiative developed to improve health outcomes, have said that treatment of PD is routinely viewed within a' medical model' resulting from the blurred boundaries between the physical, neuropsychiatric, and psychological symptoms. One inherent danger in this model is that it might be erroneously assumed that pharmacological treatment will also ameliorate mental health difficulties. This is due to the symptoms being viewed solely in the context of physiological and neurological functioning, marginalising psychological explanations and then consequently limiting access to alternative care options.

However, it is clear that mental health issues, which anyone can experience, are all related to life circumstances one way or another. Therefore, medicine and some form of talking therapy are, in most situations, the most effective way of conducting treatment concerning psychiatric symptoms.

Last year, whilst evidencing in the literature on the effectiveness of psychological approaches for treating people with neurodegenerative conditions, the Minds & Movement initiative published a set of guidelines. This compendium of theoretical and practice recommendations was produced to provide psychologists (and those wanting to adopt a psychologically informed approach) with the evidence-based framework to support people living with motor neurodegenerative conditions, including Huntington’s disease, PD, motor neurone disease, and multiple sclerosis.

In addition, similar to the Minds & Movement guidelines, there is growing evidence suggesting that psychological interventions aimed at increasing feelings of self-compassion may be valuable for people with PD. The internalised stigma around a neurological diagnosis can produce powerful feelings of shame, denial, and distress, but this can be addressed by approaches aimed at increasing self-compassion at the individual level to help counteract those understandable but detrimental emotional responses.

Finally, Ms Carr made an essential point on the palliative role of mental health practitioners in the psychological treatment of people with neurological conditions. She said it was vital that professionals actively listen to the present needs of their clients, significantly as symptoms may routinely fluctuate as the illness progresses and new symptoms surface and dissipate. She said:

“One thing I would say that when I talk to people with neurological conditions, what makes a difference is listening and proactively checking in on their mental health. Start by asking how they are; that one question can open up a whole range of things they may be willing to talk about; otherwise, you would not have known. I think it is being proactive about inquiring about how they are but also crucially listening to what they are saying and then acting on what they are saying. Because you are really working out what treatment and support they may well be needing at that time."