Without professional treatment, it may end naturally after several weeks or months. With treatment it may end much more quickly. For example, some people experience seasonal cycles of depression, particularly in winter. Five to ten percent of people who experience depression also experience states of exaggerated happiness or elation called mania. The occurrence of both depression and mania at different times is called bipolar affective disorder , while repeated experiences of depression alone is termed unipolar affective disorder.
Depression is the most treatable of mental illnesses.
Support from family, friends and self-help groups can also make a big difference. Many people who are seriously depressed wait too long to seek treatment or they may not seek treatment at all. They may not realize that they have a treatable illness, or they may be concerned about getting help because of the negative attitudes held by society towards this type of illness. It can be difficult to be with and to help someone who is seriously depressed. Some people who are depressed keep to themselves, while others may not want to be alone.