Are there any common causes of depression?

I think the most common cause for depression is a lack of satisfaction in any area of a persons life. Sometimes it can simply be not having that perfect job, but for some people they have what I personally call "the grass is greener syndrom" where every time they attain something they wanted, it seems like something else is better, and thus they become unhappy and depressed.

There are many 'causes' of depression. Some including: Trauma, breakups, death, stress.. and many other things will all have an input.

Everyone is prone to depression,some people are more prone than others due to traumatic experiences or broken families but anyone can be hit with depression it is measured by chances.The chances get higher and higher with each risk.Perfectionists are very prone due to them having trouble accepting failure,for example.

Chemical imbalances, traumatic childhood, sexual abuse, and poverty can all be causes of depression.

constant negative thoughts

Sometimes people just become sad without cause. There may be a problem which causes depression, however sometimes it just happens.

There is family stress, school/work stress, and bullying. These are brought on usually by other people, which would cause depression if you were having a hard time. There is also not getting enough sleep, or even getting too much sleep. Uneven sleeping is very unhealthy, and it is recommended that you try to go to sleep and wake up at around the same time each day. An unhealthy diet is actually a big cause of depression, or enhanced depression. You're not getting the nutrients you need if you eat Mickey D's every day! A healthy body makes a healthy mind.

A sudden death or traumatic experience in a persons life can trigger depression, things like the death of a close family member or friend.

Traumatic experiences, guilt of mistakes, loneliness, abandonment, loss, etc. There are quite a lot of different triggers.

Depression does not need to have a special cause, but it can. Sudden changes in life, traumatic experiences, loss, emotionally stressful events, work or school can all be a cause for depression regardless of your social status, age or gender although there might be a tendency.