Depression is a psychiatric syndrome seen in about 1-2% of elderly patients. When depression is seen for the first time late in life, genetic and psychosocial factors appear to be less important. Structural changes in the brain appear to be more important. In this paper the author presents the concept of arteriosclerotic depression and relates the occurrence of structural changes in the brain to atherosclerosis and the structural changes to the occurrence of depression. Evidence in support of this concept is presented.