Depression, Pain | January 5, 2016 | Author: The Super Pharmacist
Arthritis, also referred to as rheumatoid arthritis (RA), is a chronic inflammatory autoimmune disease that results in the inflammation of synovial joints that leads to tissue destruction. Patients who have RA often experience significant pain and disability as a result, and it is thought to affect approximately 0.5-1% of the general population (1).
RA is a systemic disease with a number of different manifestations of the disease in other parts of the body such as the eyes (scleritis and episcleritis), the respiratory system (pulmonary fibrosis and obliterative bronchiolitis), and the skin (leg ulcers and rashes). Many patients with RA also experience significant adverse effects on their work and social life, with movement often painful and restricted. Approximately a third of all patients stop working as a result of the condition (2), and depression is common. This may be as a result of a number of factors such as the inability to work and socialise, the resultant social isolation, or poor pain/symptom management that leaves patients in constant discomfort and a state of distress.
A number of studies have suggested that stress, worry, anxiety, trauma and depression can all either worsen the symptoms of arthritis or trigger its initial development. A prospective study of over 1500 war veterans in the United States found that those who had been diagnosed with Post Traumatic Stress Disorder (PTSD) were more than twice as likely to be diagnosed with RA, and also reported higher scores of pain (self-scored), physical impairment and tender joint count when compared to patients who had RA without PTSD (3). Another prospective cohort study, carried out in the Netherlands in the same year, also concluded that individuals with a greater propensity for worry were more likely to report increased pain scores than a cohort with lower levels of anxiety (4). Whilst the limited evidence base suggests that worrying or poor mental health does have a direct impact on the disease process, it is not always clear how. This is made doubly complicated by the limits of the qualitative methodology that is used to record pain, fatigue and disease activity scores – all this information is inherently subjective, and fatigue and pain are experienced differently and are defined differently by different patients.
There is evidence to suggest that depression is a good predictor for poorer outcomes in patients with RA. It is prevalent in patients with RA who choose to take a disability pension or cease working much earlier than patients who report having no depression or who do not exhibit depressive symptoms (5). The study, carried out by a group of German researchers in 2015, suggests that a greater understanding of the epidemiology of depression and worklessness in patients with RA would give healthcare professionals the opportunity to intervene at an earlier stage and find ways of helping people stay in employment. Another study, carried out in Korea in 2011, concluded that both being in pain can increase the likelihood of depression but that being depressed can make the pain worse. The study, focusing specifically on knee osteoarthritis (OA) in a cohort of 660 patients, observed that patients who had mild to moderate OA and depression reported much greater pain scores that patients with severe joint damage. This was despite X-rays of the mild-to-moderate patients showing an absence of the significant damage that typically indicates severe pain (6). A systematic review of all the literature examining the relationship between RA and depression noted that variation in the methods for assessing depression accounts for the differences between many of the studies that examine particular levels of depression (7). As such, caution needs to be exercised when comparing different studies with each other.
Many patients are prescribed non-pharmacological responses to RA with depression, with the most common advice concentrating on taking more exercise. Whilst this can be difficult for patients who are experiencing pain, there is evidence to suggest that increased levels of physical activity are actually very beneficial for the adequate management of RA related pain and depression (8). However, many of the studies in this particular research area are widely acknowledged as being poorly designed with significant levels of bias, so more research is required to confirm or deny this hypothesis. Additionally, physical pain and depression have a deeper biological connection than simple cause and effect; the neurotransmitters that influence both pain and mood are serotonin and norepinephrine (9). On such occasions, some healthcare professionals may combine advice for increased exercise with a pharmacological option such as an antidepressant. Therefore, antidepressants that inhibit the reuptake of both norepinephrine and serotonin have the best chance of reducing physical symptoms in patients with depression because they target the pathways that mediate both pain and depression in the brain and spinal cord (10).