Why Depression

Approximately 18.8 million American adults, or about 9.5 percent of the U.S. population have depressive disorder. Why is the number so big? What causes so many people to be depressed? I understand that depression is a legitimate disease, but I personally think that many people have some control over their state of depression.
Everyone faces saddness and hurt. It is a part of life that no one can avoid. Everybody experiences a loss of a loved one, whether it be a good friend, grandparent, parent, or sibling. Most everybody experiences a bad relationship or breakup. However, people react differently and have different attitudes towards these kind of situations. A lof of people sit and mope around when they are not in a good emotional state. They just constantly think why me and think about all the negative parts of their lives. They start to think that their world is crashing down and nothing is right. I have a good friend that just got dumped by her boyfriend. She is literally freaking out. She keeps talking about how bad her emotional state is, and how that she is not eating. She does not want to hang around any of her friends, rather she just sits in her bed by herself sulking. I understand that she is sad, but if she would just try to make the best out of the situation she would not be so depressed.
Instead of being negative people shoud try to do things that will keep their minds off of their saddness. They should go out with friends, go work out at the gym, or read a book. Anything would make them feel better than moping around. They should try to move on and recover. Just feeling sorry for themselves and dwelling on their emotions is not going to help. It is just going to make things worse.
I feel that this is the main problem with depression. If people would just have a positive attitudes they could avoid many of the symptoms of depression. It is not necessary for 9.5% of Americans to be medicated and feel like that they have some kind of major disorder. Maybe they should just try to stop sulking and look at the good they have in their life. They make the choice rather to be in a good mood or a bad mood everyday, and they should strive to always pick the good mood. Many people bring depression disorder on themselves.