Richard J. Castillo, PhD

Analyzing data gathered in a 10-nation study of psychoses by the World Health Organization (WHO), Susser and Wanderling1 found that the incidence of nonaffective psychoses with acute onset and full recovery was about 10 times higher in premodern cultures than in modern cultures. Transient psychoses with full recovery were comparatively rare in modern cultures. Such a dramatic difference begs for explanation.