Osteoarthritis (OA) is a highly prevalent condition, representing the leading cause of disability and chronic pain among older members of the population. In other words, we all have something to look forward to.
However, the degree of chronic pain suffered is varied, and does not always correlate with the changes seen on x-ray, or even MRI. Psychosocial factors are consistently associated with the symptomatology of OA: Pain and restricted function are associated with more depressive symptoms, and the existence of depression has predicted which patients might worsen over time, including who would respond better to a given treatment.
In order to understand chronic pain—including how best to treat chronic pain—the medical world needs to understand the psychological make-up of the chronic pain patient. This psychological assessment is not complete without an interpretation of how a patient’s experience of pain is related to changes in central pain processing, as dysfunctional central sensitization and descending pain inhibition have been observed in OA patients, supporting the theory that there is a large component of pain related to these phenomena. Researchers from the University of Alabama and the University of Florida published the results of a study of psychological profiles in patient with knee OA in the November, 2013 issue of “Arthritis Care & Research,” and their relationship to pain and sensory characteristics associated with pain perception.
Indeed, the researchers did find different psychological profiles in patients with knee OA; but grouping individuals together based on psychological characteristics found significant differences in clinical pain, supporting the need for a biopsychosocial model of the treatment and evaluation of pain in OA patients.
Not surprisingly, the group of individuals with the most problematic psychological profile also showed the greatest levels of pain and disability. This sort of result has already been reported. The new twist in this study is that the authors made an attempt to map psychosocial profiles to responses from quantitative survey testing. Results showed that individuals with the highest level of pain, negative mood and fatigue appeared also to be more impacted by central sensitization. On the other hand, the study subjects with the lowest level of central arousability and attention to pain and the highest level of optimism were the least sensitive to pain stimuli.
Those of us in the pain management business used to think we were so cool, as we touted our sensitivity to the psychosocial aspects of the patient. Now there are other considerations at hand: It is necessary to treat with the biopsychosocial aspects of the patient in mind. The main thing is to have enhanced ability to optimize clinical outcomes through effective and targeted therapies: For example, patients who have less negative psychosocial profiles and little evidence of central sensitization may do well with pain relief targeted at the periphery (e.g., a local injection of steroids to the knee). In contrast, patients suffering psychological distress with somatosensory pathology might benefit most from a treatment approach that adds central modulation (e.g., a central pain modulating drug such as Cymbalta) to that knee injection.
Chronic Pain and Ageing, meet Psychology. Or Biopsychosocial Psychology, I should say.