You may be surprised to learn that between 3% and 6% of the population is at risk for a form of chronic (longstanding) depression that researchers call "double depression." Like all forms of depression, double depression can cause problems with daily functioning and quality of life and carries an increased risk for suicidal thoughts or behaviors. Treatment can help, but many people delay or avoid getting the help that could save their lives.
What Is Double Depression?
Double depression is a complication of a psychiatric illness called dysthymic disorder, or dysthymia. Dysthymia is a chronic, depressed mood accompanied by just one or two other symptoms of clinical depression (such as low energy or low self-esteem) that lasts at least two years in adults (or one year in kids). This low, dark mood -- sometimes described as a "veil of sadness" -- occurs nearly every day and can sometimes persist for many years. Some people may have this mood disorder for 10 to 20 years or even more before seeking treatment.
Over time, more than half of people with dysthymia experience worsening symptoms that lead to the onset of a full syndrome of major depression superimposed on their dysthymic disorder, resulting in what is known as double depression.
How Is Double Depression Different From Major Depression Without Dysthymia?
The primary difference between a double depression and a major depression is that low-grade chronic depression precedes a full depressive syndrome in double depression but not in major depression alone. This means that for people with non-chronic major depression alone, their usual "baseline" mood is normal. But people with double depression may have never known what a normal, non depressed mood is.
In about 1 in 5 people who experience an episode of major depression, the syndrome can become chronic and persist for two years or longer. Modern diagnostic systems now classify dysthymic disorder and chronic major depression together (called "chronic depression") because they tend to be more similar than different. For most people with major depression, though, a full episode typically lasts a few weeks to a few months. There is a marked drop in mood accompanied by severe symptoms that may include:
But when a major depressive episode is effectively treated, the mood should return to normal as the other symptoms resolve. There is also often an awareness during treatment that depression is not the normal state and that things can improve.
Some of the symptoms of major depression are also present in people who have dysthymia, but they are fewer in number, less severe, and not as debilitating. They typically don't interfere with a person's day-to-day functioning as they can in major depression. As a result, people with dysthymia tend to view their symptoms as normal for them. Some may regard the low mood as a part of their personality or as simply a part of life and out of their control.
When a major depression occurs on top of a chronic depressed mood, some people with dysthymia accept it as inevitable. This causes them to delay seeking treatment and makes them more resistant to normal treatment when it does start. Plus, unless the dysthymia is addressed along with the major depression, they are not really cured when the major depression is relieved. They go back to being chronically down with the accompanying risk of a new episode of double depression.
Are There Other Characteristics of Double Depression That Make It Hard To Treat?
A recent study showed that people with double depression have a far greater sense of hopelessness than do people with dysthymia or major depression alone.
The constant stress response also causes changes in the body that increase the risk of heart disease, diabetes, and other medical conditions. The changes in the brain and the changes in the body complicate treatment for major depression when double depression occurs.
Another problem caused by the underlying, long-term depressed mood is that people with dysthymia tend to be more likely to abuse tobacco, alcohol, or street drugs or maintain an unhealthy diet. The resulting health problems further complicate treatment, and the unhealthy lifestyle choices get in the way of someone with double depression seeking treatment.
Can Double Depression Be Prevented?
The best way to prevent double depression is to treat dysthymia. Antidepressants can be helpful, but they may take longer to work and may be less effective for dysthymia than they are for acute major depression.
Cognitive therapy can also be effective in treating dysthymia. But often a combination of antidepressant medications and cognitive therapy is needed. Experts recommend starting on one approach, either cognitive therapy or an antidepressant, for a few months and watching its effect and then either switching to or adding the other if the results are not sufficient.
Exercise can help improve mood, and some studies have shown that the combination of exercise and antidepressants can have an additive effect. It also may help to improve sleep patterns because chronic sleep deprivation can worsen depression symptoms.
How Should Double Depression Be Treated?
People with dysthymia often feel as though they have little or no control over their own life. The feeling is that something else -- fate or other people -- are responsible for the course of their lives. This is not a typical feeling for people with major depression with no underlying dysthymia.
The fact that people with dysthymia have a feeling of having little or no control suggests that cognitive therapy in combination with antidepressants may be an effective treatment for double depression. The goal of cognitive therapy is to change negative thinking patterns and to give individuals new ways of seeing and dealing with themselves and their environment. Taking such an approach addresses both the major depression and the dysthymia of double depression.