Mood Disorders in Parkinson's Disease
Mood disorders are not an uncommon issue as those of us that live with the challenge of Parkinson’s can attest to. Not only does a mood disorder result in additional physical and emotional symptoms, but they aggravate those that are already present as part of the Parkinson’s diagnosis.
Depression is unfortunately very common in Parkinson’s disease, estimated to exist in 1/3 to 50% of the population affected by this chronic illness versus 1 in 10 adults in the general population. When present, it is associated with increased disability, poor quality of life, caregiver stress and increased use of the medical system, both as an inpatient and outpatient.
There are very strict criteria for diagnosing clinically significant depression (using the DSM-V criteria, a standardized classification of mental disorders for formal diagnosis). Symptoms may include:
- lack of pleasure from or interest in usually enjoyable activities
- feeling down
- difficulty concentrating
- poor energy
- sleep disturbance
- loss of appetite, weight loss
- decreased sexual energy
- feelings of worthlessness
- in severe cases, thoughts of suicide
Although the criteria for diagnosing depression are well laid out, it is not an easy task. It can be difficult to diagnose for a number of reasons. One issue is that both physicians and patients have a misconception that depressed mood is somewhat normal in the experience of chronic illness. Undoubtedly a feeling of sadness or difficulty dealing with a diagnosis of Parkinson’s is a normal part of the experience. But depressed mood that causes significant, long-lasting distress and is accompanied by serious impairment in social, occupational or other important areas of functioning (attributed to the mood issue and not PD) is not a normal adjustment reaction. Depression may also be hard to identify because some of the symptoms of depression (weight loss, sleep disturbance, fatigue etc.) are very similar to the manifestations of Parkinson’s disease. And unfortunately there is still under reporting of depressed mood due to the perceived stigma associated with such a diagnosis.
Anxiety is another mood disturbance that affects 25 – 50% of PD patients, much greater than the general population where 5 – 10% of the population is burdened by this disorder. When motor symptoms are accounted for, increasing severity of anxiety, like depression, is associated with poorer quality of life.
There are many types of anxiety disorders including:
Generalized Anxiety Disorderwhich is excessive worry about any number of issues and is associated with restlessness, fatigue, poor concentration, muscle tension, sleep disturbance and so forth.
Panic Disorderis characterized by discrete periods of intense anxiety or fear that develop rapidly and are accompanied by palpitations, sweating, amplification of tremor, shortness of breath, dizziness and often a fear of dying.
Social Phobiamay also be a manifestation of anxiety disorder in which there is marked and persistent fear of social situations, not limited to concerns about the way their Parkinson’s symptoms may be viewed by others.
Obsessive – Compulsive Disordercharacterized by persistent or repetitive thoughts or behaviors is also a type of anxiety that may be seen with increased frequency in the Parkinson’s community.
There also exists an interesting phenomenon called Nonmotor Fluctuations where mood issues (depression or anxiety) are a feature of the “off” periods in Parkinson’s patients, resulting in frequent shifts in mood, multiple times per day. Those “off” periods are usually recognizable from the poor motor symptoms and other nonmotor manifestations of the disease that also occur along with the changes in mood.
So along with the stress of dealing with the daily challenges that Parkinson’s presents, those of us that face this illness are also at increased risk for clinical mood disorders. It is important for patients and those in their support system and involved in their care to become educated and remain vigilant about these potential mood changes.
Because if not recognized and treated in a timely manner, they can significantly impact quality of life and make management of Parkinson’s in general, much more difficult.