Figure C1 summarizes graphically the description in Chapters 2 to 9 of the mental mechanisms that influence sadness and depression. It shows how the elements in a person's history and present conditions may combine to produce unfavorable self- comparisons, sadness, and depression. The aim of this figure is to present a unified picture of the depression mechanism and its elements.
Though Figure C1 is complex, please keep in mind that it is only a stylized and simplified view of the human condition, and the elements could be chosen, defined, and styled in many different fashions.