CAUSES
There is no one cause of depression that fits all. Sometimes exposure to trauma, abuse, neglect or bereavement can precipitate the development of depression. More often, it is just that the person’s life has been too hard, or too stressful for too long. Occasionally, there do not seem to be any obvious psychological or life-event causes.
In general, a marked relationship has been found between severe life events and the onset of depression. However, only a minority of people experiencing a negative life event develop depression; therefore, interaction with a biological vulnerability is likely.
In psychology, it is believed that depression results from a tendency to interpret life events in a negative way. Depressed individuals think negatively about themselves, their immediate world, and their future. These beliefs may comprise a negative blueprint, or an automatic and enduring cognitive bias about aspects of life.