Samuel Johnson was severely depressed throughout the decade of his fifties. By 62 he was cured, and the next ten years were the happiest of his entire life. I analyse these changes from a life span developmental perspective and find that Johnson's depression was a product of a developmental failure in adulthood—his inability to do the psychological work of the mid-life transition—operating upon an oedipally-based depressive character formed in childhood. I offer the hypothesis that transitional periods in the life cycle promote a regression in the personality, and that during these periods structural changes are accelerated in the relationship between the ego and the superego.