For those who have recurrent episod

For those who have recurrent episodes of major depression, the course of the illness tends to vary. Some people experience bouts of depression separated by years between episodes in which there are no symptoms. Others may have periods of several episodes. Still others may have more and more occurrences as they age. Some studies have indicated that the more depressive episodes a person experiences, the less time there is between the episodes. Also, the number of episodes a person has had may predict the possibility of having another bout with depression. Of those who have had a single major depressive episode, 50%-60% may develop a second one. About 70% of those who have had two episodes may have a third, and 90% who have had three may have a fourth.
For about two-thirds of those individuals who have a major depressive episode they will recover completely. The other one-third may recover only partially or not at all. People who do not recover completely may have a higher chance of experiencing one or more additional episodes.
It is estimated that 10%-25% of those who develop major depressive disorder have previously had dysthymic disorder, and each year about 10% of those with dysthymic disorder will develop a first major depressive episode. There are some people who have had dysthymia prior to developing major depression. The presence of both conditions at the same time is sometimes called "double depression." Those who are in this situation may have a greater chance of developing additional depressive episodes and have more difficulty fully recovering between the episodes. They may also need to have a longer period of continued care in order to overcome their symptoms.