The Synergistic Effects of Mood and Sleep on Arthritis Pain
Practical Pain Management spoke with Ajay Wasan, MD, to better understand how mood and sleep affect pain processing in OA, and how providers can help detect and manage these comorbidities.
Q: Why is adequate assessment and treatment of pain in osteoarthritis essential to care?
Dr. Wasan: Pain is the main sequela of both OA and rheumatoid arthritis and is the most disabling aspect of these diseases. Specifically, the disability and poor function resulting from arthritis pain is most impairing for patients and lowers their quality of life. In addition, arthritis pain and disability—rather than joint destruction—are the primary indications for total knee replacement and total hip replacement surgery.
Q What has your research on psychophysical and physiological responses to pain stressors in arthritis patients shown?
Dr. Wasan: As a whole, the multiple research groups that I am involved with have shown that factors other than surface joint damage play a key role in the pain experience. These factors can be classified as neuropathic and psychological.
Neuropathic symptoms in arthritis include burning, shooting, sensitivity to touch, and radiating pain. These symptoms magnify the pain and disability that people with arthritis feel and are related to problems with pain sensitivity and central/peripheral pain processing.
Psychological factors such as depression, pain catastrophizing, or heightening of negative affect correlate with increased pain severity and disability, as is true for any chronic pain condition.1
Q Why do you think patients with arthritis have a higher incidence of sleep problems?
Dr. Wasan: Research primarily by Yvonne C. Lee, MD, MMSc, and colleagues has shown that similar to other painful conditions, sleep problems can worsen pain severity and central pain processing in patients with arthritis.1 Likewise, high levels of pain can create poor sleep, which also worsens pain symptoms.2
Sleep also is associated with the cluster of negative emotions that occur in the context of pain. Thus, poor sleep independently affects pain and disability level in arthritis, and pain is linked to negative emotional symptoms and sleep disruption that go hand in hand with their effects on pain and disability.
An example of this complex relationship is demonstrated in a recent study showing that patients with OA and comorbid insomnia have significantly increased central sensitization, and that pain catastrophizing moderated the relationship between sleep efficiency and central sensitization in these patients.3
In general, psychological and sleep issues tend to have a more profound effect and occur more frequently in rheumatoid arthritis versus OA. However, there is some debate and controversy on this topic. Interestingly, while psychological and sleep issues are definitely important to consider in patients with arthritis, they may not be as prevalent as in people with chronic back pain or fibromyalgia.
Q Can depression be caused by inadequately treated arthritis pain?
Dr. Wasan: Yes, and it goes both ways. We all know that poorly controlled pain creates a heightened risk of depression. The effects of pain and depression are synergistic: depression makes the pain worse, and poorly controlled pain makes depression worse. In addition, depression is part of the constellation of negative affective symptoms—including anxiety and pain catastrophizing—that have this negative, self-reinforcing relationship with pain.
Q What tools are available to help pain practitioners screen for mood and sleep issues in arthritis patients?
Dr. Wasan: The National Institutes of Health (NIH) has a series of short, precise questionnaires for evaluating mental health known as the PROMIS (Patient-Reported Outcomes Measurement Information System). The tools can be used to evaluate mental health, as well as physical and social health, in people with chronic conditions.
The set includes short forms for evaluating depression, anxiety, sleep, and pain behavior. The tools can easily be completed by patients in the waiting room and provide a comprehensive assessment of the key domains that providers need to be aware of when evaluating and treating patients with chronic pain conditions like arthritis.
In fact, patients are used to filling out different questionnaires such as these in the waiting room and tracking their progress numerically.
Q How can pain specialists better manage mood and sleep issues in arthritis patients?
Dr. Wasan: The first step is assessment. In primary care and pain-specialty clinics, it is hard to perform a comprehensive assessment of all of the psychological factors that impact arthritis pain, but it is just so crucial because there actually are a lot more treatment tools now available than there were 20 years ago, many of which have overlapping effects on pain and mood/sleep.
For example, duloxetine is indicated for depression, anxiety, and musculoskeletal pain. Likewise, many physical therapy modalities improve not just function but mood as well. Even gentle aerobic activity such as a walking program is very effective at improving pain, mood, and sleep.