Major depression is not uncommon in people with rheumatoid arthritis (RA) – different studies have pegged the number at between 17 percent and 40 percent – but the drugs used to treat RA do little to alleviate depression, according to a systematic review presented at the 2017 British Society for Rheumatology annual conference in Birmingham, United Kingdom.
Researchers at Kings College London were interested in the effect of arthritis treatments on depression, because mood problems not only cause emotional suffering but also lead to worse physical health outcomes for people with RA.
For their study, lead author Faith Matcham, PhD, and her colleagues looked at 58 studies involving nearly 35,000 RA patients treated with 28 different arthritis medications. These included traditional disease-modifying antirheumatic drugs (DMARDs), such as methotrexate, as well as biologics and Janus kinase inhibitors (a relatively new type of targeted DMARD).
When the researchers analyzed outcomes, they found almost no change in patients’ mental well-being, no matter what arthritis medications they took. However, physical symptoms did improve – twice as much as mental ones did.
The researchers also compared different classes of drugs, such as biologics to DMARDs, as well as biologics with different modes of action to DMARDs. Again, there were only minor differences in the effect any of them had on depression.
The thought was that by using arthritis medications to treat the underlying disease, via the inflammatory pathways that drive both RA and depression, symptoms of the disease and mood would improve.
This thinking reflects both sides of the chicken-or-egg debate surrounding depression and RA. One side holds that people with RA have a higher incidence of depression as a result of their physical symptoms; the other believes depression is itself a symptom caused by chronic inflammation. Yet given the results of this study, neither theory seems to explain what happens.
The researchers didn’t look into this question directly, but recent chronic pain research may provide some clues. It’s known, for instance, that ongoing inflammation in the joints can change the way the brain and spinal cord process and transmit pain signals. The result is that pain that originates in the body is amplified in the brain – a condition known as centralized pain.
“The best analogy is that the volume control is involuntarily turned up on pain and other symptoms [that often occur with it], including depression,” explains John Davis, MD, rheumatology practice chair at Mayo Clinic in Minnesota.
Drugs targeting joint inflammation, such as those studied in the U.K. review, aren’t effective for centralized pain. As a result, doctors have tried other medications, including tricyclic antidepressants and fibromyalgia drugs. But these haven’t proved particularly effective for a large percentage of people, Dr. Davis says, and they can have serious side effects.
According to Daniel Clauw, MD, a professor at the University of Michigan Medical Center in Ann Arbor and a noted authority on chronic pain, better treatments for centralized pain and depression include daily exercise, restorative sleep and cognitive behavioral therapy.
Matcham’s team agrees that arthritis drugs alone most likely won’t help depression. “Integrated mental health care provided as part of routine physical health practice is essential to optimize both mental and physical health outcomes,” they write.
Author: Linda Rath for the Arthritis Foundation.
- How Your Mood Can Affect Bone Health
- Arthritis Affects Both Physical and Mental Health
- Arthritis & Depression