What is the Connection Between Chronic Fatigue and Depression?

Chronic fatigue and depression are closely connected. The two disorders share many symptoms, such as body aches and loss of energy. Doctors are unsure, however, if chronic fatigue and depression are triggered by each other or if having one disorder puts individuals at higher risk for the other.

The symptoms of depression vary from person to person but generally include chronic sadness or unhappiness, irritability, frustration, slowed thinking, loss of interest, changes in sleep patterns, decreased concentration, fatigue and thoughts of death or suicide. The symptoms of depression affect both mind and body and can range anywhere from mild to life-altering. The exact causes of depression are unknown, but it may be caused by trauma, stress, hormones or other biological factors. Depression can often be controlled through medications and therapy.

Chronic fatigue syndrome, or CFS, is a disorder involving constant, severe fatigue that may happen after physical or mental activity and is not relieved by rest. The exact cause of chronic fatigue syndrome is unknown, but it has been linked to anemia, hypoglycemia, depression, chronic low blood pressure, and changes in hormone levels. To be officially diagnosed with chronic fatigue syndrome, symptoms must last for at least six months and include fatigue, loss of memory and concentration, sore throat, enlarged lymph nodes, headaches, and severe exhaustion after activity.

Some doctors believe that chronic fatigue syndrome may cause some individuals to become depressed. Studies have shown that individuals with this condition are three times more likely to develop depression at some point in their lives than people who do not suffer from chronic fatigue. It is uncertain if chronic fatigue syndrome itself results in depression or if the strain and restrictiveness of the syndrome’s symptoms causes individuals to become depressed.

Long-term depression may trigger chronic fatigue. Fatigue is one symptom of depression, and studies show that those with depression are at least four times more likely to experience unexplained fatigue. Whether depression triggers chronic fatigue or chronic fatigue is a symptom of depression is not yet known.

It is possible that either problem may cause the other to develop, yet it is also possible that neither chronic fatigue nor depression triggers the other but that the two disorders are risk factors for each other. The symptoms of chronic fatigue and depression are so similar and the two disorders are so closely linked that the exact connection between them may never be defined.