Dysthymic Disorder (previously known as Dysthymia) can be diagnosed when a person has had a variety of depressive symptoms for at least two years, and these symptoms are not numerous or severe enough to qualify for Major Depressive Disorder. It can be difficult to distinguish from Major Depressive Disorder, since it is similar in terms of the types of symptoms present, and their onset and duration historically. In both disorders, individuals may have changes in their sleep patterns or appetite, low energy or fatigue, low self-esteem, poor concentration or difficulty making decisions, or hopelessness during periods of depressed mood. However, individuals with Dysthymic Disorder may have more prominent cognitive or interpersonal symptoms, such as pessimism, feelings of inadequacy, and social withdrawal.
Dysthymic Disorder often has its onset during teen years or early adulthood. When this occurs, it may negatively affect personality development, since the feelings of inadequacy and social withdrawal can interfere with achieving the important social goals of that time. As a consequence, persons with Dysthymic Disorder may be more likely to remain single and those with early onset (before age 21) more likely to develop personality disorders than those with later onset.
When there is this early onset, individuals may feel that the depression is "just the way life is," since they have never known a period of better mood and pleasure as teens or adults. As a result, many do not seek treatment until, for some reason, the depression becomes more severe. This happens fairly often, as, each year, about 10% of those with Dysthymic Disorder develop Major Depressive Disorder. Many persons with Dysthymic Disorder report that they have been depressed for decades before they finally seek treatment. Like Major Depressive Disorder, Dysthymic Disorder can cause significant impairments in occupational, academic, social, or recreational functioning.
Treatment choices are also fairly similar to those used for Major Depressive Disorder, though this has not been as well studied. There is some evidence that psychotherapy, in the forms of cognitive-behavior therapy or interpersonal therapy, may be helpful. However, many believe that anti-depressant medications are the preferred treatment, especially for those individuals who, as is often the case in this disorder, have had one or more prior unsuccessful trials of psychotherapy. There is reason to believe that treatment with a combination of psychotherapy and medication may be better for some patients, such as those with significant psychosocial stressors, marital problems, residual symptoms, or other maladaptive cognitive or behavioral habits.
It must be said that it is not clear that Dysthymic Disorder is really separate from Major Depressive Disorder. It may only differ in terms of severity and the course of the illness. Several factors suggest that the two disorders may, in fact, share some biological basis. These include 1) a similar sex ratio (women are diagnosed with these disorders about twice as often as men), 2) the fact that Dysthymic Disorder is more common among close relatives of persons with Major Depressive Disorder than in the general population, 3) the high frequency with which those with Dysthymic Disorder go on to develop Major Depressive Disorder (10% per year, as mentioned above), 4) the presence in some patients in both groups of certain abnormalities in their sleep EEGs, and 5) the similarities in methods of effective treatment.
Finally, it is important to know that Dysthymic Disorder can be successfully treated in most individuals. Because of the risk of depressive symptoms returning, it may be advisable to continue maintenance medications to prevent relapse.
Adapted with permission from the University of Michigan Depression Center Web site.