Life is full of changes. Everyday events and our reactions to them sometimes interfere with our sense of well-being and peace of mind. Sadness and feelings of grief or loss are normal reactions to such losses as divorce or separation, the death of a friend or loved one, or a job change or layoff. These feelings are an expected reaction to a "triggering event" or change that you have to get used to. Most people get over their feelings of sadness with time and gradually get their lives back under control.
If you experience feelings of sadness or loss of interest in pleasurable activities plus 4 or more of the following symptoms for 2 weeks or longer, you may have a more serious form of depression:
Contact your health professional if you experience frequent feelings of sadness or loss of interest in pleasurable activities. He or she will be able to arrange for you to receive help.
WebMD Medical Reference from Healthwise