The toll of depression can be, well, depressing.

According to the World Health Organization, depression is the leading cause of disability worldwide. In the U.S., depression afflicts just under 7 percent of adults in any given year, and about 18 percent have an anxiety disorder.

These numbers are disturbing in their own right, but if you have rheumatoid arthritis, they’re even more alarming.

[See: Am I Just Sad — or Actually Depressed?]

“Research indicates that depression and depressive symptoms are significantly more common in [people with] RA than in the general public,” says Adena Batterman, a licensed clinical social worker and the senior manager of inflammatory arthritis support and education at the Hospital for Special Surgery in New York.

“Depending on the assessment used, the rate of depression in people with RA has been reported to be between 34 and 42 percent,” Batterman explains, “and some studies suggest that the prevalence of major depression is close to 17 percent.” This is more than three times the estimated prevalence of 5 percent for major depressive disorders in the general population.

Anxiety can also accompany depression.

“Approximately 25 percent of patients with RA seen in an outpatient setting screen positive for anxiety, and 16.3 percent screen positive for both depression and anxiety,” says Lauren Holleb, a psychologist and assistant professor in the College of Science and Humanities at Husson University in Bangor, Maine.

It can be difficult to determine the true prevalence of depression in individuals with rheumatoid arthritis for several reasons.

“Most RA patients are not routinely screened for depression and anxiety,” Batterman explains. “Also, many symptoms that are commonly experienced in RA — pain, fatigue, sleep disturbances — can also be attributed to depression.

“This makes the diagnosis more challenging in this population,” she adds.

Despite these challenges, it is clear that depression is significantly more prevalent in individuals with rheumatoid arthritis than in their non-RA counterparts.

“It’s safe to say that the rates are at least double those found in the general population,” says Patricia Katz, a psychologist and professor of medicine and health policy at the University of California, San Francisco.

So why is depression so common in people with RA?

“Good question, and one to which an answer is not really known,” Katz says. “Pain associated with RA has been consistently linked with depression, as have functional limitations or loss of the ability to perform valued activities.”

[See: Coping With Depression at Work.]

Few research studies have specifically examined the relationship between depression and RA.

“The interactions and mechanisms to explain the relationship between RA and depression are still unclear,” Holleb says “It has been suggested that depression impacts RA disease activity and RA impacts depression. It is plausible that the repetitive negative thinking patterns that characterize depression may influence how patients with RA perceive their symptoms, activate the immune response and negatively impact physical behavior. These individuals may move less, have a natural loss of endorphins and have increased pain.”

“Depression and anxiety can certainly amplify or even mimic many of the symptoms of RA, particularly by being associated with increased pain and lower levels of well-being for the patient,” says Dr. Ted Mikuls, a rheumatologist in Omaha, Nebraska.

“Indeed, there have been studies suggesting that post-traumatic stress disorder — a severe form of anxiety — may even be a risk factor for the development of RA,” adds Mikuls, who is the Umbach Professor of Rheumatology in the Division of Rheumatology & Immunology, Department of Internal Medicine, at the University of Nebraska Medical Center and VA Nebraska-Western Iowa Health Care System.

It’s also daunting to be diagnosed with an incurable, chronic inflammatory condition like RA.

“A diagnosis of RA is a life-altering experience that can have a profound impact on one’s quality of life,” Batterman says. “Chronic pain and fatigue affect daily functioning. An altered sense of self and changes in relationships, work and family roles can all contribute to increased anxiety and depression.”

Additional factors may also be at play.

“The added challenge of negotiating a complex health care system, learning about and distilling complex medical information and coping with concerns and worries about treatment and medication side effects are also part of the stressors of living with this illness,” Batterman says.

And, it is possible that the disease itself may in some way increase the risk of depression.

“In the general population, depression is associated with high levels of systemic inflammation and some specific biomarkers, both of which are relevant in RA, but the role of these have not been examined in RA,” Katz explains.

[See: How to Find the Best Mental Health Professional for You.]

The medications used to treat rheumatoid arthritis may potentially improve depressive symptoms.

“Most clinical trials show some improvement in ‘mental health’ [with treatment], but depression is not usually measured,” Katz says. “Also, it’s difficult to tease out effects of disease and symptoms, such as pain and functional problems, from effects of medications.”

There is good news though. Depression and anxiety are highly treatable.

Antidepressants, anti-anxiety medications and other interventions, such as cognitive behavioral — talk — therapy, light therapy and mindfulness-based stress reduction, can all help in the treatment of depression and anxiety.

The first step, however, is to be proactive in letting your rheumatologist know if you have feelings of depression or are experiencing anxiety. Physicians today have limited time to spend with patients, so your rheumatologist may not routinely ask about depression as part of the work-up for RA.

Discussing any problems you may have with mood can also help remind him or her that depression and anxiety often go hand in hand with RA.

“The bottom line is that to treat the ‘whole patient’ we need to be thinking about underlying mental health and asking ourselves, as providers, whether underlying depression or anxiety could be explaining or amplifying the symptoms our patients are telling us about,” Mikuls says. “It may be that for some RA patients, treating [depression and anxiety] may pay bigger dividends than increasing therapy with anti-inflammatory or disease-modifying antirheumatic medications.”

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Does Rheumatoid Arthritis Impact Your Chances of Depression? originally appeared on usnews.com