Depression is a serious medical illness that involves the brain. It's more than just a feeling of being "down in the dumps" or "blue" for a few days. If you are one of the more than 20 million people in the United States who have depression, the feelings do not go away. They persist and interfere with your everyday life.
To meet criteria for depression, five or more of these symptoms must be present for more than 2 weeks:
• Ongoing sad, anxious or empty feelings
• Feelings of hopelessness
• Feelings of guilt, worthlessness, or helplessness
• Feeling irritable or restless
• Loss of interest in activities or hobbies that were once
enjoyable, including sex
• Feeling tired all the time
• Difficulty concentrating, remembering details, or difficulty
making decisions
• Not able to go to sleep or stay asleep (insomnia); may wake in the
middle of the night, or sleep all the time
• Overeating or loss of appetite
• Thoughts of suicide or making suicide attempts
• Ongoing aches and pains, headaches, cramps or digestive problems that
do not go away.
This website contains a great tutorial that is well worth watching
http://www.nlm.nih.gov/medlineplus/tutorials/depression/htm/_no_50_no_0.htm
http://www.nimh.nih.gov/health/publications/depression-easy-to-read.shtml
http://www.healthyplace.com/Communities/Depression/definition.asp
http://www.indepression.com/
