While a major depression may be triggered by some life circumstance or event, the mood reaction seems greatly exaggerated. In all likelihood, depression has less to do with events that occur than with an individual's inherent vulnerability to the condition. In rare cases, a person may experience a major depression as a single episode. However, in most instances, clinical depression tends to recur periodically, reactively or cyclically. A major depression may last up to two years.
Dysthymic disorders are milder depressive states lasting two years or more.
It is likely that these low-grade, intermittent or chronic depressive states form the temperamental basis that brings on depression. Yet for others, there is a seasonal aspect to their depression. Typically affecting people in the fall or winter, SAD is characterized by fatigue, carbohydrate craving, overeating, and oversleeping. More signs you might be depressed and what you can do about it. The information provided here is for educational purposes only, and should not be considered as offering medical advice.