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. This 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:
Insomnia or sleeping too much
- Thoughts of suicide or death
- Low self-esteem
- Loss of appetite or overeating
- Poor concentration
- Loss of interest in things that the person used to like
- Low energy or agitation
- Thoughts of worthlessness or guilt