Grant attributes the rest of her depression to the draining effects of dealing with the chronic pain of her disease. A 2003 study from Stanford University showed that people with depression were more than twice as likely to have chronic pain than people without symptoms of depression. 

And the stress of dealing with a chronic illness affects the brain, causing fluctuations in hormone levels and neurotransmitters like serotonin, which can lead to depression. Those chemical changes combined with the release of immune system cells and substances that cause inflammation predisposes people to anxiety and depression, according to a recent study in Ireland.

Medication Side Effects

If depression is a fatigue-causing factor, a wide variety of antidepressants are available to help relieve it. In fact, low doses of antidepressants often are used to treat symptoms of fibromyalgia and as fatigue treatments. But up to 20 percent of patients taking selective serotonin-reuptake inhibitor (SSRI) antidepressants, including Paxil, Prozac, or Zoloft, report drowsiness as a side effect. While you might think drowsiness would help fatigued people get the sleep they crave, daytime drowsiness related to oversedation can be a source of fatigue.

Many other medications list drowsiness as a common side effect: pain medications such as oxycodone (OxyContin); some prescription nonsteroidal anti-inflammatory drugs (NSAIDs), such as diclofenac (Voltaren) or naproxen (Naprosyn); tricyclic antidepressants such as amitriptyline hydrochloride (Endep); disease-modifying antirheumatic drugs (DMARDs) such as azathioprine (Imuran); antihistamines such as diphenhydramine (Benadryl) and some blood pressure medications.

If drowsiness or insomnia is a side effect of your medication, do not stop taking it without talking to your doctor first. Abruptly stopping medications, especially SSRIs, or missing several doses can lead to discontinuation syndrome, which causes flu-like symptoms.

Inflammation

The body’s immune system normally helps keep people healthy, fighting off illness-causing invaders. But in those with autoimmune diseases, the system targets the person’s own tissues. Researchers have found the foremost fatigue inducers to be higher-than-normal levels of cytokines – chemical messengers that regulate the intensity and duration of immune responses.

Researchers in Australia recently studied symptoms related to “acute sickness behavior.” These consisted of fatigue, malaise, listlessness, inability to concentrate, poor memory, fever and decreased appetite. The researchers interviewed 69 people with infections to learn which symptoms of acute sickness behavior they had. The researchers then measured the amount of cytokines in the patients’ blood samples and cell cultures. Results showed that fatigue consistently correlated with levels of interleukin-1 (IL-1) and IL-6, both of which are connected with inflammatory forms of arthritis. The higher the levels, the more unwell the study participants felt.

Anemia

Anemia affects up to two-thirds of RA patients and is most common in those with severe joint disease. Fortunately, if the anemia can be successfully treated, the joint pain, swelling and tenderness respond better to treatment, and improving those symptoms helps beat fatigue, according to a 2004 review of a dozen studies focusing on anemia in people with RA.