Memorandum on the Effect of Altering Mutation Rate on Incidence of Affective Psychosis Memorandum titled "Note on the effect of altering mutation rate upon the incidence of affective psychosis (manic depressive insanity including involutional depression, reactive depression, etc.)" by Penrose, for the Panel on Genetic Effects. Paper references MRC. 55/988, and CNR. 55/89. 1955