Diagnosing Depression in Parkinson's

A physician examines a patient and finds him to have slow movement, poor energy, insomnia and weight loss. Does this patient have depression? According to the DSMV-V (the Diagnostic and Statistical Manual of Mental Disorders), which serves as the universal authority for psychiatric diagnosis, this patient fits some of the criteria for depression. However in reality, this patient could also have Parkinson’s disease. Or he could have both. In fact that is the reality that many of us face. Depression may affect 30 – 50% of us at some point during the course of our illness, compared to a 10% lifetime risk in the general population.

Currently we don’t have the best tools to evaluate patients that present with the symptoms described in the opening scenario. This is one of the challenges clinicians face when it comes to diagnosing depression in the context of Parkinson’s disease. The standard criteria used to reliably diagnose depression are difficult to apply in those with Parkinson’s because it is difficult to determine which symptoms are attributable to which condition. Impaired concentration, slowness of movement or bradykinesia, sleep disorder, poor appetite, apathy and fatigue can be present in both diseases. This lack of diagnostic clarity can be detrimental to the patient and complicate the diagnostic process for the physician. Clearly changes in diagnostic criteria are necessary if these tools are going to be used successfully in the Parkinson’s community.

Another difficulty in diagnosing depression in Parkinson’s disease is that sometimes we as patients don’t recognize mood issues as being part of our disease resulting in an under-reporting of symptoms. Although there is much more available information directed towards educating patients about the non-motor symptoms of Parkinson’s disease, it is still thought of primarily as a movement disorder. However it is the non-motor issues such as sleep disturbances, pain, constipation, sexual dysfunction and of course mood disorders including depression and anxiety, that are often most responsible for poor quality of life. And if patients or their loved ones are unaware that their mood disturbance may in fact be a result of their Parkinson’s, these issues will continue to go unaddressed. Physicians rely on their patients to relay their symptoms both motor and nonmotor in order to appropriately manage them.

Another pitfall in depression being recognized and receiving treatment in Parkinson’s disease is the fact that patients, care partners and physicians as well, still may consider depressed mood to be “normal” in an ageing population or among those with chronic illness. And to some extent, receiving a diagnosis of an incurable neurologic illness is a significant stressor. But there is a difference between being stressed or sad and clinical depression. The latter may best respond to medication in addition to the therapy (CBT, cognitive behavioral treatment specifically) that would be helpful in both situations.

Lastly, a barrier that we in the Parkinson’s community struggle with as well as those in the mental health field, is the issue of perceived stigma. There is still hesitation among patients and even their loved ones to bring to light symptoms of depressed mood because of a misconception that this admission somehow diminishes them in some way – that they were weak and not strong enough to power forward. Of course this is untrue. True depression, much like Parkinson’s disease, is a result of an imbalance in the neurotransmitters or chemical messengers in the brain. It is not within your control and does not reflect on your coping ability or inner strength. Depression, like Parkinson’s or any other illness requires a comprehensive management plan including medical treatment as needed.

This is not about being sad or trying to adjust to a new reality. Depression is a significant medical illness, one that we in the Parkinson’s community are more likely to experience at some point during the course of our illness. Its presence compounds our symptoms, interferes with the management of our disease and impacts our quality of life in a very real and significant way. It needs to be recognized, spoken about and brought to the attention of our medical team so that this challenge like many others that we face, can be overcome.