Update on the epidemiology of anorexia nervosa in a defined region of Switzerland. In this follow-up investigation, the authors studied all Swiss women in the canton of Zurich who developed anorexia nervosa between ages 12 and 25 years and who were hospitalized for the first time with this diagnosis between 1983 and 1985. Data were compared with those from an earlier study, which focused on the periods 1956-1958, 1963-1965, and 1973-1975. The incidence of anorexia nervosa did not increase significantly during 1983-1985 compared to 1973-1975, in contrast to the constant increase found between 1956 and 1975. However, the more frequent use of vomiting and abuse of laxatives in 1983-1985 may indicate an increase in cases with mixed features of anorexia nervosa and bulimia. 