Chronic pain conditions like fibromyalgia, arthritis, and neuropathy cause more than mere pain — they also bring symptoms like fatigue, insomnia, frustration, and lack of motivation. According to Harvard Medical School, people suffering from chronic pain are three times more likely to develop psychiatric symptoms like anxiety or depression. People suffering depression are, conversely, three times more likely to experience chronic pain.
Doctors believe that there is a neurobiological link between depression and pain. Pain regulation relies on the same neurotransmitters as mood regulation, the theory holds, so that when the brain loses control of one of these things, it’s more likely to lose control of the other, too. Some believe the link between depression and chronic pain is so widespread, that if doctors tested all of their chronic pain patients for depression, they might find that depression plays a role in up to 60 percent of chronic pain cases. The two conditions are so closely interlinked, however, that it’s hard to say whether chronic pain causes depression, or depression causes chronic pain.
The Biochemical Links Between Pain and Depression
When someone is suffering from a painful health problem, it’s normal to assume that he or she would also experience feelings of listlessness, fatigue, lack of motivation, and frustration. Pain, whether acute or chronic, tends to cause fatigue and a loss of interest in activity, something scientists say is normal. In the case of acute pain, it’s actually beneficial — the fatigue and lethargy encourage rest, which supports the healing process. Too much activity could increase the pain and intensify the damage behind it.
Both acute and chronic pain cause chemical changes in the brain that disrupt the normal reward-seeking processes that motivate people to pursue their favorite hobbies, spend time with loved ones and generally live life. With acute pain, brain chemistry returns to normal once healing occurs and the pain subsides.
With chronic pain, however, the brain chemistry never returns to normal because the pain never subsides. Feelings of apathy, fatigue, loss of interest in pleasurable activities, and frustration stick around. Because these feelings are also hallmarks of depression, they eventually develop into psychiatric symptoms in their own right. That’s because the same parts of the brain that work to regulate pain signals rely on serotonin and norepinephrine, believed to be crucial to mood regulation. When the brain loses its ability to regulate pain signals, as it does in cases of chronic pain, it also loses its ability to regulate mood, and feelings of anxiety, hopelessness, sadness, and depression occur along with intensified feelings of pain.
A number of pain disorders are closely linked with depression, including fibromyalgia and migraine headaches. People with fibromyalgia show increased activity in the region of the brain associated with pain. People who suffer migraines are five times more likely to develop depression, while people with depression are three times more likely to develop migraines. Many people who suffer from disabling chronic pain conditions don’t even realize they have depression. Over 50 percent of people who visit their doctors complaining of chronic pain and other physical symptoms are suffering from depression, and some believe that undiagnosed depression may account for up to 60 percent of chronic pain cases, including back pain, arthritis, and headaches. Chronic pain and depression tend to feed on one another; depression makes people less likely to stick with a pain treatment program, and the pain itself can further intensify depression.
Antidepressants as Pain Medication
Underscoring all this is the fact that just about every drug used to treat depression can also be used to treat chronic pain. People suffering chronic pain conditions might take an SSRI like Zoloft (sertraline) to treat their pain symptoms. Other antidepressants used to treat chronic pain include tricyclids like amitriptyline (Elavil). Some patients use both kinds of drugs to treat chronic pain. These drugs relieve pain in much the same way they relieve depression and anxiety, by boosting levels of neurotransmitters like norepinephrine and serotonin.
Treating Chronic Pain and Depression
Antidepressant drugs are effective for treating both pain and depression, but they’re not the only weapons in the arsenal against chronic pain exacerbated by depression. Depression and pain patients can benefit from psychotherapeutic techniques that can help them learn to reduce or eliminate fearful and discouraging thoughts and adjust their daily activities to keep both emotional and physical pain at bay. Hypnosis, progressive muscle relaxation and meditation can all bring relief for both conditions. Ultimately, treating depression in patients with chronic pain — or other medical conditions — can help improve treatment outcomes for those patients.
Chronic pain and depression often occur together; scientists believe it’s because both conditions have a similar effect on neurotransmitter levels in the brain. If you’re suffering from a chronic pain condition, it’s important to be assessed for depression symptoms and get treatment for those symptoms — depression treatment could go a long way toward relieving your pain symptoms, too.