Depression is a complicated subject. Some cases of depression are caused by genetics or body chemistry. It can also be affected by stress, or even the weather. In northern countries like Norway, Sweden and Canada, people often experience Seasonal Anxiety Disorder (SAD) which is believed to be caused by long winter nights and lack of exposure to sunlight.

Suppressed anger makes people depressed.People don't know how to deal with their anger and how to express it in the right way.

Eman, people who suffer from depression might be helped by setting goals and achieving them, but this is true for everybody. It seems to me that that is not the whole story. When you look at many people who suffered severe depression, it seems that this depression ran in the family. This is true in the case of writer Ernest Hemingway and actress Margaret Sullavan. Both these people committed suicide. Both had close relatives who did the same. Just this seems to indicate that depression has a genetic component to it.

Depression is in the brain, unfortunately some of us have brains that do not produce the proper amounts of necessary chemicals to be happy.

Or perhaps something like 'everything they need to live' /'all life's necessities?' ie food, water, shelter ?