As dysthymia is a chronic disorder, sufferers may experience symptoms for many years before it is diagnosed, if diagnosis occurs at all. As a result, they may believe that depression is a part of their character, so they may not even discuss their symptoms with doctors, family members, or friends.
Dysthymia, like major depression, tends to run in families. Some sufferers describe being under chronic stress. When treating diagnosed individuals, it is often difficult to tell whether they are under unusually high environmental stress or the dysthymia is causing them to be more psychologically stressed in a standard environment.