Duration varies. Some people with anorexia nervosa have a single, relatively brief episode after experiencing an isolated stressful event. For others, the problem becomes chronic (long-lasting) and the person's condition gradually deteriorates. Many people start by restricting food, then later binge and purge. Recent research has shown that the majority of cases go away by late adolescence. But a significant number of people do have continuing problems with diet and body image into adulthood, even though the severity of the symptoms is likely to be less.