Dysthymia Dysthymia is also called chronic or minor depression. A person must have been depressed for at least 2 years to be diagnosed as having dysthymia. It is a milder form of depression that affects moods, but does not prevent a person from functioning in the world. Bipolar Depression Bipolar depression is also called manic-depression and is characterized by alternating moods of depression and elation or mania. The mood swings are most often gradual, but sometimes they can be quite sudden and dramatic.
Mania is associated with thinking and behavior that appears to be inappropriate and out of control.
It is thought that the tendency for bipolar depression may be inherited. Seasonal Affective Disorders Seasonal affective disorder is a form of depression that occurs during the winter months. It is a result of the lack of sunlight, although the exact mechanics of how this works are not completely understood. Since sunlight increases the production of serotonin in the brain, the lack of sunlight is associated with lack of serotonin production. Seasonal affective disorder is more prevalent in women than men.