1. Lipoprotein levels (St 10-20 class) of a group of patients diagnosed as psychosis with cerebral arteriosclerosis display little significant difference from a group of normals of similar age. If the level of lipoproteins (St 10-20 class) is a reflection of the activity of atheroma formation, then these patients show no more atherosclerotic activity than presumably normal individuals of the same age.2. The autopsy findings in 24 cases suggest that cerebral atherosclerosis plays an insignificant role in so-called psychosis with cerebral arteriosclerosis, the latter being due either to senile or arteriolosclerotic changes. There appears to be a trend to more "lipoidosis" as observed in the aorta, coronary, and cerebral vessels, with increasing levels of St 10-20 lipoproteins in the blood serum.Abstract Teaser